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.
Adjectives That Start with O – Full List (365 words)
Adjectives That Start with O – with Definitions and Examples
Positive Adjectives That Start with O to Describe a Person
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.
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.
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.
Definition: having unlimited power or authority; all-powerful
Synonyms: supreme, almighty, dictatorial
Example: Nature is powerful, but not omnipotent: history too often influences events.
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.
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.
Definition: very wealthy or rich; characterized by abundance; luxuriant
Synonyms: luxurious, sumptuous, palatial
Example: Most of the cash went on supporting his opulent lifestyle.
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
Definition: of irregular occurrence; happening now and then; infrequent
Synonyms: intermittent, irregular, infrequent
Example: The weather was good except for an occasional shower.
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.
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.
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.
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.
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.
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.
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.
Definition: functioning or having effect
Synonyms: in force, effective, valid
Example: The commercial telephone service was no longer operative.
Definition: required by a legal, moral, or other rule; compulsory
Synonyms: compulsory, mandatory, incumbent
Example: The college authorities have now made these classes obligatory.
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.
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
Definition: ostentatiously, costly and luxurious.
Synonyms: luxurious, sumptuous, lavish
Example: These were the glittering and opulent reminders of the medieval city.
Definition: prominent; distinguished; excellent; marked by superiority or distinction
Synonyms: excellent, marvelous, magnificent
Example: This is an area of outstanding natural beauty.
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.
Definition: serving or intended as an ornament; decorative.
Synonyms: fancy, attractive, artistic
Example: The stream was dammed up to form ornamental lakes.
Definition: elaborately or highly decorated
Synonyms: decorated, embellished, adorned
Example: The church has an ornate black and white marbled interior.
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.
Definition: having no odor, fragrance-free
Synonyms: unscented, deodorized, un-perfumed
Example: the chemical compound is not toxic as such and it is odorless.
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.
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
Definition: disagreeable; offensive
Synonyms: distasteful, unpleasant, displeasing
Example: His drunken behavior was extremely objectionable.
Definition: extremely happy
Synonyms: ecstatic, euphoric, delighted
Example: He was overjoyed to see his mother again.
Definition: Showing a cheerful willingness to do favors for others
Synonyms: helpful, accommodating, willing
Example: He is an extremely pleasant and obliging man.
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
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.
Definition: very fat; stout; corpulent
Synonyms: overweight, gross, stout
Example: Obese people tend to have higher blood pressure than lean people.
Definition: slow to understand or perceive; dull or insensitive
Synonyms: stupid, dull, unintelligent
Example: He wondered if the doctor was being deliberately obtuse.
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.
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.
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.
Definition: Resistant to guidance or discipline
Synonyms: stubborn, unyielding, inflexible
Example: The most obstinate farmers were persecuted and imprisoned.
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.
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
Definition: bigger than the usual size
Synonyms: bulging, floppy, droopy
Example: Fashion gurus dictate crazy ideas such as squeezing oversized bodies into tight trousers.
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
Definition: not discovered or known about; uncertain
Synonyms: uncertain, doubtful, unclear
Example: The origins of the tradition have become obscure.
Definition: no longer in use or practice; discarded
Synonyms: outdated, old-fashioned, outmoded
Example: Electronic banking may make over the counter transactions obsolete.
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.
Definition: offensive to morality or decency; indecent; depraved
Synonyms: indecent, salacious, smutty, pornographic
Example: In the raid, police found several boxes of obscene videotapes.
Definition: different in every way; exactly contrary
Synonyms: conflicting, incompatible, contrasting
Example: They hit a truck coming in the opposite direction.
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
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.
Definition: Showing unfeeling resistance to tender feelings
Synonyms: stubborn, obstinate, intransigent
Example: Actually, there are some fairly obdurate myths about the London climate.
Definition: (of a building, seat, etc.) being used by someone
Synonyms: inhabited, tenanted, live in
Example: Only the ground floor is fully occupied.
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
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.
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.
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.
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.