Adjectives That Start With O: 300+ O Adjectives

Adjectives are perfect for creating engaging, vivid descriptions in your writing. Strong adjectives are descriptive words that provide specific detail about something. There are many strong adjectives that start with O you can use.

No matter what you’re writing, adding more descriptive words is a great way to elevate your writing. You can also alter the tone of your writing by using adjectives. For example, a positive piece of writing will need positive adjectives.

In this article, we’ll provide you with over 300 adjectives that start with O, which you can use for different writing scenarios.

O Words to Describe Someone

If you need to describe someone in a creative piece, or for a personnel review, you could use some adjectives starting with O in your writing.

When you pick an adjective, check if the definition matches what you want to convey to your reader. Is that description exactly what you’re going for? When you’ve picked an adjective, you can check its definition by searching for it in an online dictionary.

It’s also important to think about your target audience and whether they will understand what the adjective means. For example, you could describe someone as “obtuse,” but there are several definitions of the word. The obtuse definition here would be someone who lacks a quick intellect.

Here’s a list of adjectives that start with O, which you can use to describe someone:

• Oafish

• Obedient

• Obeisant

• Obese

• Objectionable

• Objective

• Obligate

• Obligated

• Obliging

• Oblique

• Oblivious

• Obnoxious

• Obscene

• Obsequious

• Observant

• Observational

• Obsessed

• Obsessional

• Obstetric

• Obstinate

• Obstreperous

• Obstructive

• Obstruent

• Obtrusive

• Obtuse

• Obvious

• Occidental

• Occlusal

• Occlusive

• Occupational

• Octogenarian

• Odd

• Odd-looking

• Oddball

• Odiferous

• Odious

• Odorous

• Off-key

• Off-kilter

• Offbeat

• Offensive

• Offhand

• Offhanded

• Official

• Officiary

• Offline

• Ogreish

• Okay

• Old

• Old-fashioned

• Old hat

• Old-school

• Old-world

• Older

• Oldest

• Olympian

• Olympic

• Ominous

• Omnipotent

• Omnipresent

• Omniscient

• Omnivorous

• Oncological

• One-legged

• One-sided

• Oneiric

• Onerous

• Online

• Open

• Open-minded

• Openhanded

• Openhearted

• Opportunistic

• Opposing

• Oppressive

• Optimistic

• Opulent

• Orange

• Ordinary

• Organized

• Oriental

• Original

• Ornery

• Orphaned

• Orthopedic

• Ostentatious

• Otherworldly

• Outgoing

• Outlandish

• Outlaw

• Outraged

• Outrageous

• Outspoken

• Outstanding

• Overactive

• Overaggressive

• Overambitious

• Overassertive

• Overbearing

• Overcautious

• Overconfident

• Overcritical

• Overemotional

• Overenthusiastic

• Overjoyed

• Overoptimistic

• Overpowering

• Overprotective

• Overqualified

• Overrated

• Oversensitive

• Oversized

• Overweight

• Overwhelmed

• Overwhelming

• Overworked

• Overzealous

Compliments That Start With O

You can use adjectives in compliments if you want to share some positive feedback with someone about their work or efforts. It’s important to be specific about your compliment if you want to sound sincere, as it shows you’ve put more thought into your comments.

Positive adjectives beginning with O are good to use in compliments, as they give the right tone to suggest the person you’re complimenting has impressed you.

For example, if you wanted to compliment someone on their personality, you could say you appreciate their optimistic views and how outgoing they are. If they’ve impressed you with being able to manage their time well, you could comment on how organized they are.

Here is a list of adjectives that start with O to use in your compliments:

• Obliging

• Observable

• Observant

• Observed

• Obstructed

• Occurrent

• Official

• Officiary

• Olent

• Olympic

• Omakase

• On-screen

• Oneiric

• Ongoing

• Open

• Open-minded

• Operational

• Operative

• Opportune

• Optimal

• Optimistic

• Optimum

• Optional

• Opulent

• Organized

• Original

• Outgoing

• Outspoken

• Outstanding

• Overall

• Overjoyed

• Own

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Funny Words That Start With O

Funny adjectives are words you can use to describe something humorous, or they could be funny sounding when people read them. Humor is certainly subjective, though, so some people may find a word funny that others do not.

Some describing words beginning with O are funny based on the connotations they have. For example, in the children’s film Shrek, Shrek says that ogres are like onions, so by his own definition, you could say ogres are “oniony,” which makes that a funny word.

Here is a list of funny adjectives that start with O:

• Oafish

• Obfuscatory

• Oblate

• Oblique

• Oblong

• Obnoxious

• Obstreperous

• Obtuse

• Occupiable

• Ocreate

• Octahedral

• Octal

• Octangular

• Octoid

• Octonocular

• Octopean

• Octopine

• Octopodous

• Odd-looking

• Oddball

• Oddish

• Odiferous

• Odinic

• Odoriferous

• Ogreish

• Ohmic

• Old hat

• Ole

• Oleophilic

• Oligemic

• Omnibus

• Omphalic

• Onanistic

• Oniony

• Onymous

• Oozy

• Optical

• Orbital

• Ornery

• Outlandish

• Oxymoronic

Negative Words That Start With O

Negative adjectives are used to describe something often regarded as undesirable. You could also use negative words to create a negative tone, if that’s something you are aiming for in your writing.

Some negative words have negative connotations, and you can use them in specific instances to suggest something sad or unpleasant. For example, the word “off-limits” refers to areas you are not allowed to enter, such as backstage at a music festival. Therefore, if you see a sign saying an area is “off-limits,” you know not to go in there. 

Here’s a list of negative adjectives that start with O:

• Obituary

• Objectionable

• Obligational

• Obligatory

• Obliterable

• Obliterated

• Obliterative

• Oblivious

• Obnoxious

• Obscene

• Obscure

• Obsessed

• Obsessive

• Obsolescent

• Obsolete

• Obstinate

• Obstreperous

• Obstructed

• Obstructive

• Obverse

• Occult

• Odious

• Odorous

• Oedipal

• Off

• Off-air

• Off-center

• Off-key

• Off-kilter

• Off-limits

• Off-peak

• Off-putting

• Offending

• Offensive

• Offhand

• Offhanded

• Officious

• Offish

• Offside

• Offtrack

• Ogreish

• Oily

• Oleaginous

• Oligopolistic

• Oligotrophic

• Omissible

• Omissive

• One-sided

• Onerous

• Only

• Opinionated

• Opponent

• Opposable

• Opposed

• Opposing

• Opposite

• Oppressive

• Orchestrated

• Ornery

• Ostentatious

• Outdated

• Outlandish

• Outlaw

• Outraged

• Outrageous

• Overaggressive

• Overambitious

• Overassertive

• Overbearing

• Overcast

• Overcautious

• Overconfident

• Overcooked

• Overcritical

• Overcrowded

• Overdue

• Overemotional

• Overenthusiastic

• Overlooked

• Overoptimistic

• Overpowering

• Overpriced

• Overrated

• Overt

• Overwhelmed

• Overwhelming

• Overworked

• Overwrought

• Overzealous

Cute Words That Start With O

If you need to describe something as cute, you can use adjectives to add more details to paint a better picture in your reader’s mind.

For example, you might write a fantasy story and want to describe a cute tree that is important to the people in your story. You could refer to it as “the old tree,” but the word “old” is quite negative and doesn’t give the impression that the tree is cute.

Instead, you could refer to the tree as “the ole oak tree.” The difference between “old” and “ole” is that the latter sounds more respected and well regarded by people. The word “ole” is also more commonly found in the fantasy genre, where specific adjectives create imagery fantasy readers already understand.

Here is a list of adjectives that start with O, which you might use to describe something cute:

• Oak

• Objectional

• Obliging

• Obtainable

• Oceangoing

• Oceanic

• Ocellar

• Ocellated

• Ochreous

• Octagonal

• Octahedral

• Octonary

• Ogival

• Okay

• Ole

• Olent

• Oleraceous

• Olive

• Olympic

• One

• Oneiric

• Onyx

• Opalescent

• Operatic

• Optimistic

• Opulent

• Orange

• Orchestral

• Organic

• Original

• Ornamental

• Ornate

• Oscine

• Our

• Outdoor

• Oval

• Overjoyed

There you have it, over 300 adjectives that start with O you can use in your writing to create more specific descriptions.

If you’re not sure that your writing has enough adjectives, or you want to check you’ve included sensory descriptions in your writing, you can use some of ProWritingAid’s reports.

The ProWritingAid Thesaurus report will highlight all the adjectives in your writing so you can identify any paragraphs where you might lack concrete details. Try adding some adjectives from this list to create more engaging descriptions.

Once you find a word you want to use, pop it into the Word Explorer on the ProWritingAid website to see the definition and some usual synonyms. There’s also a reverse dictionary, which provides words that have the opposite definition.

If you’re following the “show, don’t tell” rule, try ProWritingAid’s Sensory report. The report highlights places where you have used sensory descriptions such as touch, smell, and visual. If you don’t see many results when using the Sensory report, try using some adjectives starting with O to create more vivid descriptions.

There are thousands of adjectives in the English language, so we’re just scratching the surface in our list of adjectives that start with O. We hope our list helps you find a better adjective for your writing.