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Big List of Adjectives That Start With O (Positive, Negative, Descriptive)

Adjectives consist of a part of the speech, which is responsible for modifying nouns and pronouns. There is a multitude of adjectives that begins with the letter O. Continue reading to see a massive list of all English words that are both adjectives and begin with the letter “O”.

Adjectives that start with O
Adjectives that start with O

Adjectives that start with “O”

It is normal to find obscure and obvious adjectives that begin with this letter. Without further ado, let us get into the list of adjectives that start with O:

  • Obedient
  • Oral
  • Ornery
  • Occasional
  • Obscure
  • Occupational
  • Occidental
  • Occupied
  • Orange
  • Orangish
  • Ominous
  • Oceanic
  • Ornate
  • Odd
  • Odd-looking
  • Official
  • Oily
  • Opulent
  • Odiferous
  • Ordinary
  • Opened
  • Openhanded
  • Openminded
  • Organic
  • Orthopedic
  • Operable
  • Odorous
  • Odious
  • Original
  • Odor
  • Open
  • Ornamental
  • Orphan
  • Orphaned
  • Offbeat
  • Opposable
  • Oafish
  • Offensive
  • One
  • Opaque
  • Obese
  • Opposed
  • Offhanded
  • Outermost
  • Omnivorous
  • Objectionable
  • Objective
  • Officious
  • Obligatory
  • Operatic
  • Outer
  • Odorless
  • Operational
  • Obliging
  • Off
  • Oblique
  • Outstanding
  • Older
  • Overactive
  • Ostentatious
  • Operative
  • Oblivious
  • Outspoken
  • Oval
  • Omniscient
  • Outraged
  • Omnipresent
  • Oldest
  • Other
  • Opinionated
  • Obtainable
  • Overqualified
  • Otherwise
  • Overambitious
  • Opposite
  • Opportune
  • Overaggressive
  • Outgoing
  • Overcrowded
  • Opportunist
  • Overcautious
  • Overwrought
  • Outward
  • Oblong
  • Our
  • Obvious
  • Old
  • Overenthusiastic
  • Overrated
  • Obnoxious
  • Okay
  • Obtrusive
  • Overall
  • Obscene
  • Observable
  • Overassertive
  • Overpowering
  • Overjoyed
  • Observant
  • Overconfident
  • Outlandish
  • Obsolete
  • Own
  • Overt
  • Obstinate
  • Obstructive
  • Overcooked
  • Outrageous
  • Ominous
  • Overbearing
  • Onerous
  • Outside
  • Overcast
  • Outcast
  • Overcritical
  • Overemotional
  • Overzealous
adjectives that start with O
Adjectives that start with O

Descriptive Adjectives That Start with O

Descriptive adjectives consist of an adjective, which tends to modify a pronoun or noun by choosing to describe it or express its quality.

Let us take some examples here:

  • Peter is an obedient student.
  • The skunk released a very bad odor from its body.

Did you notice the descriptive adjectives that were used in these two sentences? ‘Obedient’ and ‘Odor’ are the descriptive adjectives used.

Both of these words are describing the nouns that they are modifying. It tells us information that we can utilize for describing the things they refer to.

Let us look at some of the descriptive adjectives that start with O:

  • Obedient – Willing or choosing to comply with a request or an order.
  • Obese – Someone who is overweight and fatter than the average individual.
  • Oblivious – Unconcerned and unaware of the things happening in the surrounding.
  • Obnoxious – A person who is extremely unpleasant.
  • Observant – Quickly able to perceive and notice things and behavior.
  • Obscene – Displaying disgusting and sexually inappropriate acts.
  • Obsessive – Constantly filling the mind with something or someone in an unhealthy way.
  • Oily – Something that contains oil.
  • Old – A person who isn’t young anymore.
  • Older – A sibling that’s more in age than the other.
  • Omnivorous – A person or animal that consumes both meat and plants.
  • Opportunist – An individual who exploits opportunities immediately, mostly through unfair means.
  • Optimistic – Confident and hopeful quality concerning the future.
  • Orange – A citrus fruit that’s round and big in appearance.
  • Ordinary – No distinctive and special features.
  • Orphan – A child without parents.
  • Outgoing – Someone who is friendly and socially available and present all the time.
  • Overaggressive – Excessively belligerent.
  • Overambitious – Excessively ambitious.
  • Overqualified – Someone with lots of accolades and experience.
  • Overemotional – Easily showing feelings even in simple situations.
  • Oversensitive – A person that easily gets offended.
  • Overrated – Valued or rated too highly and kept on a pedestal.
  • Overzealous – Extremely passionate in one’s behavior or attitude.

Positive Adjectives That Start with O

Positive adjectives offer some of the best wordplays. You can use the following words to brighten up someone’s day:

  • Obliging – An accommodating person who is ever-ready to help and do favors.
  • Observant – Someone who notices things immediately.
  • Orotund – Rich and clear speech or sound.
  • Opportune – Executed at the right time.
  • Outstanding – Marked by distinction and superiority.
  • Odds-on – Possessing a fair shot of winning or succeeding at something.
  • Optimal or Optimum – Favorable or best.
  • Okay – Accepted or correct.
  • Optimistic – An individual who has a hopeful view of the future.
  • Omnicompetent – Someone who has the ability to deal with all types of situations and matters.
  • Overjoyed – Super delighted and happy.
  • Opulent – Filled with abundance; extremely wealthy.
  • Opalescent – The ability to display a plethora of colors. Constantly changing colors in a slight manner.
  • Orderly – Tidy or well-organized.
  • Open-hearted – A benevolent and kind person.
  • Originative – The ability to create or produce something.
  • Open-minded – Someone who is open to new ideas and corrections.
  • Ornate – Embellishment; elaborate.
  • Outgoing – A social butterfly.

Negative Adjectives That Start with O

Positive words are excellent self-affirmations. But let us also look into the negative adjectives that start with O:

  • Objectionable – Something that is deemed as offensive and unpleasant. Arousing opposition and distaste.
  • Ostentatious – Showy display in order to impress people. Pretentiousness.
  • Obtrusive – Intrusively noticeable. Unwelcoming.
  • Overbearing – Overpowering in an unpleasant way.
  • Overloaded – Placing excessive amount of burden on someone or something.
  • Oblique – Something that is evasive and slanting.
  • Obtuse – Slow in perceiving or understanding. Something that is insensitive and dull.
  • Obliterated – To fully wipe out or destroy something or someone.
  • Odious – Super unpleasant. Revolting and repulsive.
  • Oblivious – A forgetful or unmindful person.
  • Offensive – To cause a person to be upset, resentful, or annoyed.
  • Obscene – Offending moral principles. Sexually explicit content.
  • Opportunistic – Someone who takes advantage of the situation for personal gains. Ulterior motives.
  • Overblown – When something is exaggerated to seem more important when it’s actually not.
  • Officious – Assertive and authoritative in a domineering way. Extremely aggressive in providing help and services.
  • Obscure – An uncertain thing or undiscovered. Hard to understand.
  • Onerous – Involvement of a lot of effort, which can feel quite burdensome in an oppressive way.
  • Ominous – Giving off the impression or sign that something unfortunate and malicious is going to happen.
  • Obstinate – Extremely stubborn and opinionated, especially in changing one’s decision or opinion regardless of the persuasive attempts by the opposing party.
  • Obstructive – Blockage, interruption, hindrance, and continuous delays.
  • Opinionated – A conceited or stubborn individual who isn’t open to actual evidence and strongly sticks to their beliefs.
  • Oppressive – Choosing to inflict harsh and brutal treatment on a group of people or an individual.
  • Oversimplified – It is simplified to the extent where there is misrepresentation of facts.

Adjectives That Start with O to Describe a Person

Now, let us take a look into the adjectives that start with O to describe a person. This list of adjectives that start with O includes:

  • Oafish – It is used to describe someone who is rough, unintelligent, and clumsy.
  • Obedient – A person who follows through. Disciplined.
  • Overcritical – Passing judgements, remarks, and unwarranted comments in a disapproving way.
  • Obnoxious – A nasty and distasteful individual.
  • Overbold – Someone who is not afraid to be themselves. Excessively bold and outspoken.
  • Obsessive – An unhealthy pattern of stalking or obsessing over someone out of love or hatred.
  • Ordinary – Common and not unusual.
  • Odd – Contrary to what is expected or seen as normal; strange.
  • Odious – Very unpleasant and offensive. Revolting or disgusting behavior.
  • Offensive – An insulting or derogatory remark or action that hurts a person or group of people.
  • Old – A person who has lived long and experienced many things in life.
  • Opinionated – A person who highly regards his merits and is stubborn of their beliefs.
  • Optimistic – Someone who is always cheerful and thinks positively about life in general. They remain hopeful even in bad situations.
  • Otiose – Something or someone that doesn’t serve any practical result or purpose.
  • Outgoing – An extroverted person. Someone who socializes a lot.
  • Outraged – Arousal of shock or fierce anger as a reaction to something bad.
  • Outrageous – Excessively bad and shocking behavior.
  • Overmodest – Excessively unassuming when it comes to one’s achievements and abilities.
  • Overaged – Crossing a certain or specific age limit.
  • Overweight – Unhealthy body weight.

Example Sentences Using Adjectives That Start With “O”

Next, let’s put some of these adjectives into sentences to give you clarity on the topic of discussion.

  • I am openminded. It’s in my interest to try everything once.
  • Have you seen the new Miss Fresher? Her beauty is one of a kind.
  • You are being incredibly obnoxious right now.
  • Our class has oral presentation on Monday.
  • Joseph was overjoyed by the sight of his father’s surprise visit at the airport.
  • My diet usually consists of greens and protein. However, I do love to engage in the occasional burger and pizza fiesta every now and then.
  • My therapist advised me to be more optimistic about the future.
  • The ornate detailing in the painting caught our attention.
  • Human beings are omnivorous by default.
  • Congratulations, your performance on the final examination was outstanding.
  • The opposing political party has an evil agenda.
  • It was an opportune moment for Tanya to confess her grievances to the faculty.
  • The French fries were extremely oily. It was rather unhealthy to eat it.

Adjectives that start with “O” (images)

Adjectives that start with O
Adjectives that start with O
Adjectives that start with O
Adjectives that start with O

Other adjective lists

Other lists of adjectives:


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About the author

Dalia Y.: Dalia is an English Major and linguistics expert with an additional degree in Psychology. Dalia has featured articles on Forbes, Inc, Fast Company, Grammarly, and many more. She covers English, ESL, and all things grammar on GrammarBrain.

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