365 Adjectives That Start with O | List with Definitions and Examples
As you may know, adjectives that start with O are not so plenty as other alphabets, like B, C, S… But still, they are equally important and indispensable in English language.
Adjectives starting with O are used to describe or modify nouns pronouns, making your writing and speaking much more specific, and a lot more interesting. Let’s take a look at some examples including adjectives beginning with O.
- There is an open suitcase on the ground.
- My brother and I live on opposite sides of the city.
- It’s an obvious fact that Jim loves her.
- This is just an ordinary book.
We can see by adding descriptive words that start with O in above sentences, the messages they convey are immediately clear and specific.
Continue reading to get a full list of adjectives that start with O, as well as definitions and examples.
Table of Contents
Adjectives That Start with O – Full List (365 words)
To begin with, I am sharing with you a list of adjectives starting with O. And some of these O adjectives are quite commonly used and helpful in everyday life.
- Oafish
- Oaken
- Oaten
- Obdurate
- Obedient
- Obese
- Objectionable
- Objective
- Oblanceolate
- Oblate
- Obligate
- Obligated
- Obligational
- Obligatory
- Obliging
- Oblique
- Obliterable
- Obliterate
- Obliterated
- Oblivious
- Oblong
- Obnoxious
- Obovate
- Obscene
- Obscure
- Obsequious
- Observable
- Observant
- Observational
- Observing
- Obsessional
- Obsessive
- Obsolescent
- Obsolete
- Obstetric
- Obstetrical
- Obstinate
- Obstreperous
- Obstructed
- Obstructive
- Obtainable
- Obtrusive
- Obtuse
- Obvious
- Occasional
- Occidental
- Occipital
- Occluded
- Occlusive
- Occult
- Occupational
- Occupied
- Occurrent
- Oceangoing
- Oceanic
- Ocellated
- Ocher
- Ochre
- Octagonal
- Octal
- Octangular
- Octogenarian
- Octosyllabic
- Octuple
- Ocular
- Odd
- Oddish
- Odiferous
- Odious
- Odoriferous
- Odorless
- Odorous
- Odourless
- Oecumenic
- Oecumenical
- Offbeat
- Offenseless
- Offensive
- Offhand
- Offhanded
- Official
- Officious
- Offish
- Offshore
- Offside
- Offstage
- Ohmic
- Oily
- Old
- Olden
- Oldish
- Oldline
- Oleaceous
- Oleaginous
- Oleophilic
- Oleophobic
- Olfactive
- Olfactory
- Oligarchic
- Olive
- Olivelike
- Olympian
- Olympic
- Omani
- Ominous
- Omissible
- Omissive
- Omnibus
- Omnidirectional
- Omnifarious
- Omnipotent
- Omnipresent
- Omniscient
- Omnivorous
- Oncologic
- Oncoming
- One
- Oneiric
- Onerous
- Onetime
- Ongoing
- Online
- Only
- Onomastic
- Onshore
- Onside
- Onstage
- Ontogenetic
- Ontological
- Onymous
- Oozy
- Opalescent
- Opaline
- Opaque
- Open
- Opencast
- Opencut
- Openhanded
- Openhearted
- Openmouthed
- Operable
- Operant
- Operatic
- Operating
- Operational
- Operative
- Operculate
- Operculated
- Operose
- Ophthalmic
- Opinionated
- Opinionative
- Opponent
- Opportune
- Opportunistic
- Opposed
- Opposing
- Opposite
- Oppositive
- Oppressive
- Opprobrious
- Optative
- Optic
- Optical
- Optimal
- Optimistic
- Optimum
- Optional
- Opulent
- Oracular
- Oral
- Orange
- Orangish
- Oratorical
- Orbicular
- Orbiculate
- Orbital
- Orbitual
- Orchestral
- Ordained
- Ordered
- Orderly
- Ordinal
- Ordinary
- Organic
- Organicistic
- Organisational
- Organised
- Organismal
- Organismic
- Organizational
- Organized
- Orgiastic
- Oriental
- Orientated
- Oriented
- Original
- Originative
- Ornamental
- Ornate
- Ornery
- Ornithological
- Oropharyngeal
- Orotund
- Orphaned
- Orphic
- Orthodox
- Orthogonal
- Orthomolecular
- Orthopaedic
- Orthopedic
- Orthopedical
- Orthoptic
- Orthostatic
- Orthotropous
- Orwellian
- Oscine
- Oscitant
- Osseous
- Ossicular
- Ossiculate
- Ossiferous
- Ossified
- Osteal
- Ostensible
- Ostensive
- Ostentatious
- Other
- Otherwise
- Otherworldly
- Otic
- Otiose
- Ototoxic
- Ottoman
- Outback
- Outboard
- Outbound
- Outbred
- Outcast
- Outcaste
- Outclassed
- Outdated
- Outdoor
- Outer
- Outermost
- Outflowing
- Outgoing
- Outlandish
- Outlaw
- Outlawed
- Outlying
- Outmoded
- Outmost
- Outraged
- Outrageous
- Outre
- Outrigged
- Outright
- Outside
- Outsized
- Outspoken
- Outspread
- Outstanding
- Outstretched
- Outward
- Oval
- Ovarian
- Ovate
- Over
- Overabundant
- Overactive
- Overaged
- Overaggressive
- Overall
- Overambitious
- Overanxious
- Overarm
- Overbearing
- Overblown
- Overbold
- Overburdened
- Overbusy
- Overcareful
- Overcast
- Overcautious
- Overconfident
- Overcooked
- Overcredulous
- Overcritical
- Overcrowded
- Overcurious
- Overdelicate
- Overdressed
- Overdue
- Overemotional
- Overenthusiastic
- Overexcited
- Overfamiliar
- Overfed
- Overfond
- Overfull
- Overgenerous
- Overgreedy
- Overgrown
- Overhand
- Overhanded
- Overhasty
- Overhead
- Overheated
- Overindulgent
- Overjealous
- Overjoyed
- Overladen
- Overland
- Overlarge
- Overlying
- Overmodest
- Overmuch
- Overnice
- Overnight
- Overoptimistic
- Overpowering
- Overpriced
- Overprotective
- Overproud
- Overqualified
- Overrated
- Overrefined
- Overripe
- Oversea
- Overseas
- Oversensitive
- Overserious
- Oversewn
- Oversexed
- Overshot
- Oversize
- Oversized
- Oversolicitous
- Overstrung
- Overstuffed
- Oversubscribed
- Oversuspicious
- Overt
- Overvaliant
- Overweening
- Overweight
- Overwhelmed
- Overwhelming
- Overworked
- Overwrought
- Overzealous
- Oviform
- Ovine
- Oviparous
- Ovoid
- Ovoviviparous
- Owing
- Owlish
- Own
- Owned
- Ownerless
- Oxidative
- Oxidised
- Oxidizable
Adjectives That Start with O – with Definitions and Examples
To know more details about these adjectives beginning with O, check their definitions and examples.
- Oafish
Definition: rough or clumsy and unintelligent
Example: He called me a stupid, oafish, little girl in front of everyone the night I met him.
- Oaken
Definition: made of oak wood
Example: The warriors carried huge oaken shields.
- Oaten
Definition: made of oats or oat straw
Example: The first product was an oaten biscuit, released in 1992.
- Obdurate
Definition: used to describe a person who refuses to change their mind, or someone or something that is difficult to deal with or change
Example: Several obdurate facts remain, preventing a compromise solution.
- Obedient
Definition: doing, or willing to do, what you have been told to do by someone in authority
Example: He always tried his best to be an obedient son.
- Obese
Definition: extremely fat
Example: Obese people tend to have higher blood pressure than lean people.
- Objectionable
Definition: unpleasant, offensive, or repugnant
Example: He want people to stop making objectionable content so we’re less tempted to consume it.
- Objective
Definition: not influenced by personal feelings or beliefs
Example: Analysts produced objective evidence that the world was heading for a global recession.
- Obligatory
Definition: expected because it usually happens
Example: Several Secret Service agents surrounded the President, all wearing the obligatory raincoat and hat.
- Obliging
Definition: willing or eager to help
Example: He found an obliging doctor who gave him the drugs he needed.
- Oblique
Definition: not expressed or done in a direct way
Example: He issued an oblique attack on the President.
- Oblong
Definition: having a shape that is longer than it is wide
Example: It’s a shrub with narrow, oblong leaves.
- Obnoxious
Definition: very pleasant or rude
Example: Some of the colleagues say that he’s loud and obnoxious.
- Obscure
Definition: not clear and difficult to understand or see
Example: His answers were obscure and confusing.
- Obscene
Definition: offensive, rude, or shocking, usually because of being too obviously related to sex or showing sex
Example: He was jailed for making obscene phone calls.
- Obsequious
Definition: obedient or attentive to an excessive or servile degree
Example: They were served by obsequious waiters.
- Observable
Definition: that can be noticed or seen
Example: There’s no observable connection between the two events.
- Observant
Definition: obeying religious rules or customs
Example: As an observant Muslim, she wore a headscarf.
- Obsessive
Definition: of the nature of an obsession
Example: I love that obsessive quality.
- Obsolete
Definition: not in general use any more, having been replaced by something newer and better or more fashionable
Example: We need to replace some obsolete equipment.
- Obstetric
Definition: relating to the area of medicine that deals with pregnancy and the birth of babies
Example: The hospital needs to be able to offer 24-hour obstetric services.
- Obstetrical
Definition: of or pertaining to childbirth or obstetrics
Example: On obstetrical examination of the giraffe, a fetal malposition type of dystocia had occurred.
- Obstinate
Definition: used to describe a problem, situation, or thing that is difficult to deal with, remove, change or defeat
Example: Invading troops met with obstinate resistance by guerilla forces.
- Obstreperous
Definition: noisy and difficult to control
Example: The boy is cocky and obstreperous.
- Obstructive
Definition: causing a blockage or obstruction.
Example: All tubing should be cleared of obstructive algae and detritus.
- Obtuse
Definition: annoyingly insensitive or slow to understand
Example: I like a bit obtuse reporting.
- Obvious
Definition: easily perceived or understood; clear, self-evident, or apparent.
Example: Unemployment has been the most obvious cost of the recession.
- Occasional
Definition: not happening or done often or regularly
Example: I play the occasional game of tennis.
- Occidental
Definition: relating to the western part of the world, especially the countries of Europe and America
Example: The music is a mix of occidental pop and Latin sensuality.
- Occipital
Definition: relating to the occipital area
Example: A scan of the girl’s brain showed seizure activity in the temporal, parietal, and occipital lobes of the brain.
- Occlusive
Definition: of or relating to the act of occlusion
Example: Look in the ingredients for occlusive agents that will prevent water loss, such as ceramides and petrolatum.
- Occult
Definition: relating to magical powers and activities, such as those of witchcraft and astrology
Example: She claims to have occult powers, given to her by some mysterious spirit.
- Occupational
Definition: relating to or caused by your job
Example: Back problems are an occupational hazard for any desk-bound office worker.
- Oceanic
Definition: belonging or relating to an ocean or to the sea
Example: Many oceanic islands are volcanic.
- Ocher
Definition: having a yellowish-orange color
Example: The building has ocher yellow walls and green tiled roofs.
- Octagonal
Definition: having eight straight sides
Example: There were pictures on every other wall of the octagonal shaped room.
- Odd
Definition: strange or unexpected
Example: Her father was an odd man.
- Odious
Definition: extremely unpleasant
Example: Herr Schmidt is certainly the most odious man I have ever met.
- Odorous
Definition: having an unpleasant smell
Example: The chlorine dioxide neutralizes the odorous sulphur compounds.
- Odorless
Definition: having no odour
Example: Carbon monoxide is colorless, odorless and tasteless and persists in the air.
- Offbeat
Definition: not coinciding with the beat
Example: A rapid tempo is essential here, otherwise we will not sense the offbeat hemiolas.
- Offensive
Definition: used for attacking
Example: Knives of any kind are classed as offensive weapons.
- Offhand
Definition: not showing or not done with much thought or consideration
Example: His offhand manner disturbed us.
- Official
Definition: relating to a position of responsibility
Example: He visited China in his official capacity as America’s trade representative.
- Officious
Definition: assertive of authority in a domineering way, especially with regard to trivial matters
Example: The security people were very officious.
- Offshore
Definition: situated at sea some distance from the shore
Example: This huge stretch of coastline is dominated by offshore barrier islands.
- Offside
Definition: on or relating to the side of a vehicle that is furthest from the edge of the road and closest to the centre of the road when you are driving on right side
Example: The offside rear wheels need replacing.
- Offstage
Definition: (in a theatre) not taking place on the stage and so not visible to the audience
Example: She walked away as the clear winner of both onstage and offstage dancing.
- Oily
Definition: covered in oil or containing a lot of oil
Example: I have oily skin.
- Old
Definition: having lived for a long time; no longer young
Example: The old man lay propped up on cushions.
- Olden
Definition: for a long time ago
Example: There weren’t things like televisions and computers in the olden days.
- Oldish
Definition: somewhat old
Example: The typewriter, an oldish electric model, stood on the dinning-table.
- Oldline
Definition: used to describe a business or industry that has existed for a long time
Example: It’s the latest old-line industry to disappear from the region.
- Oleaginous
Definition: rich in, covered with, or producing oil; oily
Example: Fabrics would quickly become filthy in this oleaginous kingdom.
- Olfactive
Definition: of or relating to sense of smell
Example: The olfactive descriptions of floral scent from each species was evaluated for a professional perfumer.
- Olfactory
Definition: concerned with the sense of smell
Example: This olfactory sense develops in the womb.
- Olympian
Definition: having the qualities of a god
Example: She has maintained an Olympian detachment from the everyday business of the office.
- Ominous
Definition: suggesting that something unpleasant is likely to happen
Example: There was an ominous silence when I asked whether my contract was going to be renewed.
- Omnidirectional
Definition: sending or receiving signals in all directions
Example: It also demonstrates a nearly omnidirectional radiation pattern.
- Omnipotent
Definition: having the power to do anything
Example: The people overthrew the once omnipotent dictator.
- Omnipresent
Definition: present or having an effect everywhere at the same time
Example: The singer became an omnipresent icon of style and beauty.
- Omnivorous
Definition: naturally able to eat both plants and meat
Example: Pigs are omnivorous animals.
- Oncoming
Definition: moving towards you or coming nearer
Example: The car veered onto the wrong side of the road and hit an oncoming truck.
- Oneiric
Definition: like a dream, or relating to dreams
Example: The film thrills with its indelible, oneiric imagery.
- Onerous
Definition: causing great difficulty or trouble
Example: The tax bill was aimed at lifting the onerous tax burden from the backs of the middle class.
- Onetime
Definition: only once
Example: The gym charges a separate, onetime fee to join.
- Ongoing
Definition: continuing to exist or develop, or happening at the present moment
Example: There are a number of ongoing difficulties with the project.
- Online
Definition: products, services, or information that can be bought or used on the internet
Example: We’re linked to the online database at our head office.
- Only
Definition: used to show that there is a single one or very few of something, or that there are no others
Example: I have the only person on the train.
- Onshore
Definition: on land rather than in the sea
Example: The energy supplier has invested heavily in developing onshore windfarms.
- Oozy
Definition: of, resembling, or containing mud; slimy
Example: The tank, with its mouldering brickwork, its rusty iron, its dank shrubs and weeds, its oozy canal, had vanished like smoke in the air.
- Opalescent
Definition: colorless or white like an opal, or changing color like an opal
Example: Elaine turned her opalescent eyes on him.
- Opaque
Definition: not able to be seen through, not transparent
Example: Bottles were filled with a pale opaque liquid.
- Open
Definition: allowing access, passage, or a view through an empty space; not closed or blocked
Example: He climbed through the open window.
- Opencast
Definition: (of mines and mining) excavated from the surface
Example: The mine developed as a series of opencast working, mainly by the use of hydraulic mining methods.
- Open-mouthed
Definition: having an open mouth, esp. in surprise
Example: There must be many thousands of small businessmen hearing this with open-mouthed astonishment.
- Operable
Definition: fit, possible, or desirable to use; practicable
Example: Check operable safety features of the car before driving.
- Operant
Definition: involving changes in behaviour that are caused because good or bad things always happen in connection with the behaviour
Example: As part of the operant conditioning, the cat was rewarded with food when he remained calm during each step of the procedure.
- Operatic
Definition: extravagantly theatrical; histrionic
Example: She wrung her hands in operatic despair.
- Operational
Definition: relating to a particular activity
Example: There are operational advantages in putting sales and admin in the same building.
- Opinionated
Definition: having strong opinions and refuse to accept that they may be strong
Example: Your article is full of some of the most opinionated rubbish I have ever read.
- Opportune
Definition: happening at a time that is likely to produce success or is convenient
Example: This seems to be an opportune moment for reviving our development plan.
- Opportunistic
Definition: using a situation to get power or on advantage
Example: He made an opportunistic grab for power, which resulted in a civil war.
- Opposed
Definition: (of two or more things) contracting or conflicting with each other
Example: The agency is being asked to do two diametrically opposed things.
- Opposing
Definition: competing or fighting against each other
Example: The article tries to show opposing viewpoints on the issue.
- Opposite
Definition: situated on the other or further side when seen from a specified or implicit viewpoint; facing
Example: A crowd gathered on the opposite side of the street.
- Oppressive
Definition: (of weather) close and sultry
Example: The day was sunless and oppressive.
- Optic
Definition: relating to the eye or vision
Example: Once the optic nerve was severed during the surgery, the surgeon knew the patient would receive the vision without allowing an impulse to the brain.
- Optical
Definition: relating to light or the ability to see
Example: The glowing cloud was an optical effect.
- Optimal
Definition: the best or most effective possible in a particular situation
Example: Companies benefit from the optimal use of their resources and personnel.
- Optimistic
Definition: hoping or believing that good things will happen in the future
Example: She is optimistic about her chances of winning a gold medal.
- Optimum
Definition: best; most likely to bring success or advantage
Example: A mixture of selected funds is an optimum choice for future security and return on investment.
- Optional
Definition: available to be chosen but not obligatory
Example: There are several optional tours, for which there will be a small charge.
- Opulent
Definition: rich in appearance; showing great wealth
Example: He lived an opulent lifestyle that included sports cars and enormous homes.
- Oracular
Definition: of or relating to an oracle
Example: Apollo had his oracular shrine at Delphi.
- Oral
Definition: spoken rather than written; verbal
Example: They had reached on oral agreement.
- Orange
Definition: of a color between red and yellow
Example: The setting sun filled the sky with a deep orange glow.
- Ordered
Definition: well-organized and has a clear structure
Example: An objective set of rules which we all agree to accept is necessary for any ordered society.
- Orderly
Definition: well-arranged or organized
Example: She put the letters in three orderly piles.
- Ordinary
Definition: with no special or distinctive features; normal
Example: He sets out to depict ordinary people.
- Organic
Definition: not using artificial chemicals in the growing of plants and animals for food and other products
Example: These organic olives are packaged in recycled glass containers.
- Organizational
Definition: relating to the action of organizing something
Example: She has great organizational skills.
- Organized
Definition: arranged according to a particular system
Example: The letters had been placed in organized piles, one for each letter of the alphabet.
- Orgiastic
Definition: wild, uncontrolled behaviour and feeling of great pleasure and excitement
Example: People who put up pagan mistletoe at a Christian ceremony must expect orgiastic behaviour.
- Oriental
Definition: relating to the countries of East and Southeast Asia
Example: The concrete floor was covered with oriental rugs.
- Oriented
Definition: used to describe what someone or something is mainly interested in or concerned with
Example: It just show how much she really has a family-oriented mindset.
- Original
Definition: existing since the beginning, or being the earliest form of something
Example: The gardens have recently been restored to their original glory.
- Ornamental
Definition: used or grown for ornament
Example: There was a big rectangular poo, not deep, which Thomas Robertson had stocked with ornamental fish.
- Ornate
Definition: language that tis ornate contains too many complicate words or phrases
Example: Some students are put off studying his work because of the ornate language of the poetry.
- Ornery
Definition: likely to get angry and argue with people
Example: He had been in an ornery mood all day, arguing with everyone who got in his way.
- Ornithological
Definition: relating to the study of birds
Example: She works as a sketch artist for an ornithological magazine.
- Oropharyngeal
Definition: relating to the oropharynx
Example: Sixty patients with oral and oropharyngeal carcinomas were enrolled.
- Orphaned
Definition: having no parents because they have died
Example: The family took in three orphaned siblings.
- Orthodox
Definition: (of beliefs, ideas, or activities) considered tradition, normal, and acceptable by most people
Example: We would prefer a more orthodox solution to the problem.
- Orthogonal
Definition: (of a square matrix) defined so that is product with its transpose results in the identity matrix
Example: An orthogonal matrix, combining the selected levels of attributes, was used to define scenarios.
- Orthomolecular
Definition: relating to a method of treating chemical imbalances in the body by use of vitamins
Example: She has a private practice in orthomolecular nutrition.
- Orthoptic
Definition: relating to the treatment or study of problems of the eye muscles, for example having a squint or having double vision
Example: Orthoptic examination and treatment is important in the rehabilitation of low-vision patients.
- Orthostatic
Definition: relating to standing up straight
Example: If you feel that your blood pressure changes because of the posture and position you are holding, you may be suffering from orthostatic hypotension.
- Orwellian
Definition: used to describe a political system in which the government tries to control every part of people’s lives, similar to that described in the novel “Nineteen Eighty-Four”, by George Orwell
Example: We don’t want to see a 1984 Orwellian type situation where neighbours are reporting on neighbours.
- Osseous
Definition: composed of, containing, or resembling bone; bony
Example: Histological diagnosis was reported as osseous cavernous hemangioma.
- Ossified
Definition: (of habits or ideas) fixed and unable to change
Example: He tried to push liberalizing policies through an ossified bureaucracy.
- Osteal
Definition: osseous; bony
Example: Presumably, these variations may induce osteal obstruction, preventing mucus drainage and predisposing to chronic rhinosinusitis.
- Ostensible
Definition: stated or appearing to be true, but not necessarily so
Example: The real dispute which lay behind the ostensible complaint.
- Ostentatious
Definition: too obviously showing your money, possessions, or power, in an attempt to make other people notice and admire you
Example: They criticized the ostentatious lifestyle of their leaders.
- Other
Definition: as well as the thing or person already mentioned
Example: The product has many other time-saving features.
- Otherworldly
Definition: more closely connected to spiritual things than to the ordinary things of life
Example: The children in the picture look delicate and otherworldly, as though they had never run or played.
- Ototoxic
Definition: causing damage to the ear
Example: The ototoxic effects of radiotherapy have been poorly characterized.
- Ottoman
Definition: of or relating to the Ottomans or the Ottoman Empire
Example: Under a Ottoman threat of war he obtained in 1826 the convention of empire.
- Outback
Definition: of such a region
Example: This outback area is a far cry from the city’s concrete jungle.
- Outboard
Definition: (of an electronic accessory) in a separate container from the device with which it is used
Example: The computer resides in a single cabinet plus some outboard boxes for disk drives.
- Outbound
Definition: travelling away from a particular point
Example: There has been an increase in outbound traffic leaving Toronto airport for the Caribbean resort.
- Outdated
Definition: old-fashioned and therefore not as good or as fashionable as something modern
Example: Many hospitals struggle with outdated equipment and facilities.
- Outdoor
Definition: existing, happening, or done outside, rather than inside a building
Example: The hotel has an outdoor swimming pool.
- Outer
Definition: at a greater distance from the centre
Example: Ice had formed around the outer edge of the pond.
- Outermost
Definition: further away
Example: These spacecrafts may send back data about the outermost reaches of the solar system.
- Outgoing
Definition: (of a person) friendly and energetic and finding it easy and enjoyable to be with others
Example: She has an outgoing personality.
- Outlandish
Definition: strange and unusual
Example: She liked to dress in outlandish clothes.
- Outlying
Definition: far away from main towns and cities, or far from the centre of a place
Example: Many of the students travel in by bus from outlying areas.
- Outmoded
Definition: no longer modern, useful, or necessary
Example: Outmoded working practices are being phased out.
- Outmost
Definition: most remote; outermost
Example: The outmost islands are rich in various resources but have not been managed yet.
- Outraged
Definition: feeling outrage
Example: Outraged viewers jumped onto social media to complain about the ending of the series.
- Outrageous
Definition: unacceptable, offensive, violent, or unusual
Example: He made outrageous claims.
- Outright
Definition: complete
Example: There was no outright winner in the election.
- Outside
Definition: coming from another place or organization
Example: The company has called in outside experts.
- Outsized
Definition: (of profits, payments, etc) extremely large and are considered too large by many people
Example: Companies can’t just ramp up their production capacity and expect to earn outsized profits.
- Outspoken
Definition: expressing strong opinions very directly without worrying if other people are offended
Example: Mr. Masack is an outspoken critic of the present government.
- Outspread
Definition: to spread out, extend; expand
Example: Adults have been observed resting with outspread wings on lichen-covered tree-trunks.
- Outstanding
Definition: clearly very much better than what is usual
Example: It’s an area of outstanding natural beauty.
- Outstretched
Definition: (especially of a hand or arm) extended or stretched out
Example: She reached across and shook his outstretched hand.
- Outward
Definition: relating to how people, situations, or things seen to be, rather than how they are inside
Example: The outward appearance of the building has not changed at all in 200 years.
- Oval
Definition: shaped like a circle that is flattened so that it is like an egg or an ellipse
Example: The plant has oval green leaves marbled with brownish-purple.
- Ovarian
Definition: of or pertaining to an ovary
Example: Nearly half of women with ovarian cancer see their GP three times before they are diagnosed.
- Ovate
Definition: shaped like an egg
Example: The cones are very small, ovate and pointed.
- Overabundant
Definition: too abundant; excessive
Example: We are bombarded with food advertising and an overabundant supply of high fat and high sugar foods.
- Overactive
Definition: (of part of the body) producing too much of a substance, or reacting too quickly
Example: With an overactive thyroid, metabolism speeds up.
- Overaged
Definition: over a certain age limit
Example: The college has many overaged students.
- Overaggressive
Definition: excessively quarrelsome or belligerent
Example: Overaggressive banks poured money they did not have into worldwide expansion.
- Overall
Definition: in general, rather than in particular, or including all the people or things in a particular group or situation
Example: The overall situation is good, despite a few minor problems.
- Overambitious
Definition: excessively ambitious
Example: She is let down by her overambitious structure and a lack of sufficient tension.
- Overanxious
Definition: excessively worried, tense, or uneasy
Example: It’s often fragile, the way she talks, but elegant, with big eyes a window into an overanxious brain.
- Overarm
Definition: done with the hand or arm passing above the level of the shoulder
Example: The bowler was happy to demonstrate his overarm technique.
- Overbearing
Definition: too confident and too determined to tell other people what to do, in a that is unpleasant
Example: Milligan had a pompous, overbearing father.
- Overblown
Definition: stout; obese
Example: Sometimes in the overblown world of modern football, things just need to be said the way they are.
- Overburdened
Definition: having too much to carry, contain, or deal with
Example: We’re trying to stop development in areas with overburdened roads and schools.
- Overcareful
Definition: excessively careful
Example: Across the street, she imagined the man with the rockets taking overcareful arm at her.
- Overcast
Definition: with clouds in the sky and therefore not bright and sunny
Example: The sky was overcast.
- Overconfident
Definition: having or showing too much confident
Example: Overconfident brashness may not impress an interview panel.
- Overcritical
Definition: inclined to find fault too readily
Example: The overcritical teacher can discourage originality.
- Overcrowded
Definition: (of accommodation or a space) filled beyond what is comfortable, safe, or desirable
Example: Infectious diseases can spread in overcrowded prisons.
- Overdressed
Definition: dressed too elaborately or finely
Example: She was overdressed for the party.
- Overdue
Definition: not paid on time
Example: The company routinely takes money off wages to collection on overdue debts.
- Overemotional
Definition: having feeling that are too easily and displayed
Example: We’re not an overemotional family.
- Overenthusiastic
Definition: excessively enthusiastic
Example: It is a salutary warning to the overenthusiastic reader.
- Overexcited
Definition: excessively excited
Example: They were forced to hide from overexcited fans who threatened to riot.
- Overfamiliar
Definition: too well acquainted with
Example: The overfamiliar use of her Christian name was intentional.
- Overfull
Definition: containing an excessive amount of something
Example: The two singers describe their overfull boat which apparently has a childish look as travelling on a path of hope.
- Overgenerous
Definition: excessive willing and liberal in giving away one’s time, money, etc
Example: It follows measures to stop grade inflation from overgenerous exam marking.
- Overgrown
Definition: grown too large or beyond its normal size
Example: The town is only an overgrown village.
- Overhasty
Definition: excessively hasty
Example: Hard times are showing up overhasty mergers.
- Overhead
Definition: above your head, usually in the sky
Example: This room needs overhead lighting.
- Overheated
Definition: having become or been made too hot
Example: Let the overheated engine cool off.
- Overindulgent
Definition: allowing someone to have more of something enjoyable than is good for them
Example: In part, the researchers pointed to overindulgent adults for raising children to believe they are special no matter what they do.
- Overladen
Definition: having too heavy a load
Example: It’s a wonder she doesn’t sink into the earth, like an overladen cart on a muddy road.
- Overland
Definition: (of travel) across the land, and not by sea or air
Example: They’re taking an overland trip across Canada.
- Overlarge
Definition: excessively large
Example: This tendency is particularly clear in the overlarge section devoted to the 1970s.
- Overmuch
Definition: (especially in negatives) too much or very much
Example: I don’t have overmuch confidence in Hal.
- Overnight
Definition: for or during the night
Example: I emptied the closet and put my belongings into the black overnight case.
- Overoptimistic
Definition: unjustifiable optimistic
Example: These overoptimistic forecasts encourage savers to expect unrealistic bumper returns.
- Overpowering
Definition: too strong to be able to continue or resist
Example: Fighters were driven back by the overpowering heat of the flames.
- Overpriced
Definition: too expensive; costing more than it is worth
Example: I went and had an overpriced cup of coffee in the hotel cafeteria.
- Overprotective
Definition: wishing to protect someone, especially a child, too much
Example: The children of overprotective parents often do not develop the skills they need to take care of themselves when they leave home.
- Overqualified
Definition: too highly qualified for a particular job
Example: An overqualified person will quickly become dissatisfied.
- Overrated
Definition: (of something or someone) considered to be better or more important than they really are
Example: In my opinion, she’s a hugely overrated singer.
- Overseas
Definition: in, from, or connected with another country or countries, especially across the sea
Example: We need to open up overseas markets.
- Oversensitive
Definition: excessively or unduly sensitive
Example: The problem was traced to an oversensitive protection circuit, a type of circuit breaker.
- Oversize
Definition: bigger than usual or too big
Example: My daughter loves to wear oversize clothes.
- Overstuffed
Definition: filled with too much material or too many things
Example: They sat in overstuffed crimson leather chairs.
- Overt
Definition: done or shown publicly or in an obvious way and not secret
Example: He shows no overt sign of his unhappiness.
- Overweight
Definition: heavier than is allowed
Example: If your luggage is overweight, you have to pay extra.
- Overwhelming
Definition: very great in amount
Example: His party won overwhelming support.
- Ovoid
Definition: having the same shape as an egg, or of a similar shape
Example: The ovoid seed pods burst when ripe.
- Owlish
Definition: (of glasses) resembling the large round eyes of an owl
Example: Her owlish glasses made her look studious.
- Own
Definition: belonging to or done by a particular person or thing
Example: They can’t handle their own children.
- Ownerless
Definition: having no owner
Example: Their ownerless property is destroyed.
- Oxidizable
Definition: able to be oxidized
Example: Organic oxidized carbon was also observed in the forest soils.
Positive Adjectives That Start with O to Describe a Person
Without adjectives, we won’t be able to express how a person is like. Below are some adjectives that start with O to describe a person to help you out in such case in daily life.
1. Obedient
Definition: complying or willing to comply with an order or request; submissive to another’s authority
Synonyms: compliant, tractable, amenable
Example: He was always obedient to his father’s wishes.
2. Obliging
Definition: ready to do favors; helpful; courteous; accommodating
Synonyms: helpful, accommodating, willing
Example: He found an obliging doctor who gave him the drugs he needed.
3. Observant
Definition: paying careful attention; keenly watchful; perceptive or alert
Synonyms: alert, sharp-eyed, eagle-eyed
Example: An observant shop assistant had remembered exactly what the man was wearing.
4. Omnipotent
Definition: having unlimited power or authority; all-powerful
Synonyms: supreme, almighty, dictatorial
Example: Nature is powerful, but not omnipotent: history too often influences events.
5. Omniscient
Definition: knowing everything, all-seeing
Synonyms: all-knowing, all-wise
Example: In other words, only an omniscient analyst can judge the degrees of cost and pay-off to both utterer and receiver.
6. Optimistic
Definition: having the tendency to take the most hopeful or cheerful view of matters or to expect the best outcome
Synonyms: cheerful, positive, hopeful
Example: I’m very optimistic about our chances of success.
7. Opulent
Definition: very wealthy or rich; characterized by abundance; luxuriant
Synonyms: luxurious, sumptuous, palatial
Example: Most of the cash went on supporting his opulent lifestyle.
8. Open-minded
Definition: willing to consider new ideas; unprejudiced
Synonyms: unbiased, unprejudiced, accepting
Example: Try to keep an open mind until you’ve heard all the facts.
Positive Adjectives That Start with O to Describe an Event
Some adjectives require a certain context to be uttered. For example, below descriptive words that start with O can be used when describing an event.
1. Occasional
Definition: of irregular occurrence; happening now and then; infrequent
Synonyms: intermittent, irregular, infrequent
Example: The weather was good except for an occasional shower.
2. Opaque
Definition: not letting light pass through; not transparent or translucent; not reflecting light; not shining or lustrous;
Synonyms: dull, dark, cloudy, blurred
Example: You can always use opaque glass if you need to block a street view.
3. Opportune
Definition: happening or done at the right time; seasonable; well-timed; timely
Synonyms: suspicious, propitious, favorable
Example: This would seem to be an opportune moment for reviving our development plan.
4. Original
Definition: having to do with an origin, first, earliest; fresh, new, novel; capable of or given to inventing or creating something new, or thinking or acting in an individual, fresh way; coming from someone as the originator, maker, author, etc
Synonyms: indigenous, native, first, early
Example: Never be afraid to be yourself. Remember, an original is worth more than a copy.
5. Orthodox
Definition: conforming to the usual beliefs or established doctrines, as in religion, politics, etc.; approved or conventional
Synonyms: conservative, traditional, devout
Example: We would prefer a more orthodox approach/solution to the problem.
6. Ostentatious
Definition: characterized by or given to pretentious or conspicuous show in an attempt to impress others
Synonyms: showy, conspicuous, obtrusive
Example: They criticized the ostentatious lifestyle of their leaders.
7. Obtainable
Definition: capable of being acquired
Synonyms: available, in circulation, in season
Example: Buff Fitness Center assured obtainable results for every client simply by sticking to a daily 45-minute exercise.
8. Ongoing
Definition: something that is still going on at the present time and is going to continue
Synonyms: underway, in progress, happening
Example: Training is part of our ongoing career development program.
9. Operative
Definition: functioning or having effect
Synonyms: in force, effective, valid
Example: The commercial telephone service was no longer operative.
10. Obligatory
Definition: required by a legal, moral, or other rule; compulsory
Synonyms: compulsory, mandatory, incumbent
Example: The college authorities have now made these classes obligatory.
11. Occupational
Definition: relating to a job or profession
Synonyms: professional, vocational, business
Example: For many years, experts in occupational health have puzzled over symptoms reported by office workers, including headache, nausea and fatigue.
12. One-time
Definition: Belonging to some prior time
Synonyms: sometime, erstwhile, as was
Example: The scholarship is available on a competitive basis and is a onetime award.
Positive Adjectives That Start with O to Describe a Place
The more adjectives you learn, the more freedom you’ll get when trying to express yourself in everyday life. So keep on learning the following adjectives that start with the letter O.
1. Opulent
Definition: ostentatiously, costly and luxurious.
Synonyms: luxurious, sumptuous, lavish
Example: These were the glittering and opulent reminders of the medieval city.
2. Outstanding
Definition: prominent; distinguished; excellent; marked by superiority or distinction
Synonyms: excellent, marvelous, magnificent
Example: This is an area of outstanding natural beauty.
3. Open
Definition: someone or something which is not closed
Synonyms: unlocked, unfolded, unlatched
Example: He could see a green open space just beyond; and then the woods seemed to be thicker and darker.
4. Ornamental
Definition: serving or intended as an ornament; decorative.
Synonyms: fancy, attractive, artistic
Example: The stream was dammed up to form ornamental lakes.
5. Ornate
Definition: elaborately or highly decorated
Synonyms: decorated, embellished, adorned
Example: The church has an ornate black and white marbled interior.
6. Oaken
Definition: Consisting of or made of wood of the oak tree
Synonyms: oak tree, oak wart, woody
Example: A new oaken enclosure was built and new wiring and electric bellows bought.
7. Odorless
Definition: having no odor, fragrance-free
Synonyms: unscented, deodorized, un-perfumed
Example: the chemical compound is not toxic as such and it is odorless.
8. Official
Definition: Given official status as a national or state institution
Synonyms: formal, ceremonial, pompous
Example: The mayor presented him with a gold medal at an official city reception.
9. Offshore
Definition: At some distance from the shore
Synonyms: away from the shore line, shoreward
Example: His money is in an offshore island bank.
Positive Adjectives That Start with O to Describe Emotions, Personality, and Feelings
Without adjectives, it is basically impossible to express our feelings. Are you “glad”, “sad”, “angry”, “excited”? These are all common adjectives used in day-to-day life. And below are more adjectives with letter O for similar use.
1. Objectionable
Definition: disagreeable; offensive
Synonyms: distasteful, unpleasant, displeasing
Example: His drunken behavior was extremely objectionable.
2. Overjoyed
Definition: extremely happy
Synonyms: ecstatic, euphoric, delighted
Example: He was overjoyed to see his mother again.
3. Obliging
Definition: Showing a cheerful willingness to do favors for others
Synonyms: helpful, accommodating, willing
Example: He is an extremely pleasant and obliging man.
4. Obvious
Definition: easily perceived or understood; clear, self-evident, or apparent
Synonyms: evident, clear, conspicuous
Example: Lack of qualifications is an obvious disadvantage.
Negative Adjectives That Start with O to Describe a Person
If you can’t find a proper word to describe the person you hate, the following adjective words that start with O to describe a person may help.
1. Odd
Definition: different to what is usual or expected; strange
Synonyms: strange, peculiar, weird
Example: As a manager, it is so hard to deal with odd workers.
2. Obese
Definition: very fat; stout; corpulent
Synonyms: overweight, gross, stout
Example: Obese people tend to have higher blood pressure than lean people.
3. Obtuse
Definition: slow to understand or perceive; dull or insensitive
Synonyms: stupid, dull, unintelligent
Example: He wondered if the doctor was being deliberately obtuse.
4. Offensive
Definition: unpleasant, as to the senses; disgusting; repugnant; causing resentment, anger, etc
Synonyms: insulting, rude, derogatory
Example: His comments were deeply offensive to a large number of single mothers.
5. Oafish
Definition: Ill-mannered and coarse, contemptible in behavior or appearance
Synonyms: stupid, foolish, idiotic
Example: My fellow, oafish roommate has shared my computer with me periodically.
6. Oblivious
Definition: not aware of or concerned about what is happening around one
Synonyms: unaware, heedless, insensible
Example: He seemed oblivious to the fact that he had hurt her.
7. Obstinate
Definition: Resistant to guidance or discipline
Synonyms: stubborn, unyielding, inflexible
Example: The most obstinate farmers were persecuted and imprisoned.
8. Obstructive
Definition: causing or tending to cause deliberate difficulties and delays
Synonyms: uncooperative, awkward, disobliging
Example: Mr Smith was obstructive and refused to follow correct procedure.
9. Old
Definition: having lived for a long time; no longer young
Synonyms: elderly, mature, aged
Example: There is no better looking-glass than an old friend
10. Oversized
Definition: bigger than the usual size
Synonyms: bulging, floppy, droopy
Example: Fashion gurus dictate crazy ideas such as squeezing oversized bodies into tight trousers.
11. Oily
Definition: containing oil
Synonyms: greasy, fatty, buttery
Example: When she was younger, she had very oily skin.
Negative Adjectives That Start with O to Describe an Event
If you are a non-English speaking and hope to sound more native, try to include following describing words beginning with O in you daily talks.
1. Obscure
Definition: not discovered or known about; uncertain
Synonyms: uncertain, doubtful, unclear
Example: The origins of the tradition have become obscure.
2. Obsolete
Definition: no longer in use or practice; discarded
Synonyms: outdated, old-fashioned, outmoded
Example: Electronic banking may make over the counter transactions obsolete.
3. Opposing
Definition: set against; placed opposite, in balance or contrast; contending with in speech or action
Synonyms: rival, opposite, combatant
Example: The soldiers battled against the opposing army all day.
4. Obscene
Definition: offensive to morality or decency; indecent; depraved
Synonyms: indecent, salacious, smutty
Example: In the raid, police found several boxes of obscene videotapes.
5. Opposite
Definition: different in every way; exactly contrary
Synonyms: conflicting, incompatible, contrasting
Example: They hit a truck coming in the opposite direction.
6. Offline
Definition: not controlled by or directly connected to a computer or the internet.
Synonyms: disconnected, logged off, connectionless
Example: If one or more modules are offline, you will need to repeat this call when all modules are available online.
Negative Adjectives That Start with O to Describe a Place
Adjectives are what make a sentence colorful and appealing. But you have to use choose the correct ones and use them correctly. Check below adjectives that start with O together with definitions, synonyms and examples to help you better understand them.
1. Odorous
Definition: having or giving off an odor
Synonyms: smelly, stinking, reeking
Example: This can in fact be quite useful in some circumstances such as where a person works in an odorous environment.
2. obdurate
Definition: Showing unfeeling resistance to tender feelings
Synonyms: stubborn, obstinate, intransigent
Example: Actually, there are some fairly obdurate myths about the London climate.
3. Occupied
Definition: (of a building, seat, etc.) being used by someone
Synonyms: inhabited, tenanted, live in
Example: Only the ground floor is fully occupied.
4. Odoriferous
Definition: having or giving off a smell, especially an unpleasant one
Synonyms: aromatic, pungent, savory
Example: These odoriferous organic compounds contain numerous ingredients generally classified into four main groups which are characteristic of the majority of essential oils.
Negative Adjectives That Start with O to Describe Emotions, Personality, and Feelings
List of adjectives that start with O is kind of small in comparison to other more common letters, which means less time and efforts needed to master them all.
1. Ominous
Definition: giving the worrying impression that something bad is going to happen; threateningly inauspicious
Synonyms: menacing, baleful, sinister
Example: There was an ominous silence at the other end of the phone.
2.Outrageous
Definition: having the nature of, involving, or doing great injury or wrong; exceeding all bounds of decency or reasonableness; very offensive or shocking; unrestrained
Synonyms: shocking, disgraceful, appalling
Example: I must make apologies for my outrageous behavior.
3. Obnoxious
Definition: extremely unpleasant, causing disapproval
Synonyms: nasty, distasteful, disagreeable
Example: I have been in restaurants where the human customers have been loud, rude and obnoxious.
4. Oppressive
Definition: inflicting harsh and authoritarian treatment
Synonyms: harsh, cruel, brutal
Example: The oppressive afternoon heat had quite tired him out.
Final Thoughts on Adjectives That Start with O
Do you like these adjectives that start with the letter O we sorted out for you? We hope you find them helpful.
Generally, nouns are one of the most important parts of speech. But adjectives make your speech more accurate and understandable. The thing with adjectives is you never want to overdo them.
Too many adjectives can bulk up a sentence, reducing its fluidity. So remember, only to use these adjectives that start with O where appropriate.
Ps. See also positive words that start with O, nouns that start with O and verbs that start with O.
