515 Best Adjectives that Start with O | O Adjectives

Adjectives that Start with O! In this section, you will learn a list of common words that start with O in English with ESL picture and example sentences to help you enhance your vocabulary words.

Table of Contents

Adjectives that Start with O

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
Off
Offbeat
Offended
Offenseless
Offensive
Offhand
Offhanded
Official
Officious
Offish
Offshore
Offside
Offstage
Ohmic
Oily
OK
Old
Olden
Old-fashioned
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
Open-handed
Openhearted
Open-hearted
Opening
Open-minded
Openmouthed
Operable
Operant
Operatic
Operating
Operational
Operative
Operculate
Operculated
Operose
Ophthalmic
Opinionated
Opinionative
Opponent
Opportune
Opportunistic
Opposable
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
Overweening
Overweight
Overwhelmed
Overwhelming
Overworked
Overwrought
Overzealous
Oviform
Ovine
Oviparous
Ovoid
Ovoviviparous
Owing
Owlish
Own
Owned
Ownerless
Oxidative
Oxidised
Oxidizable
Obeisant
Obsessed
Obstruent
Occlusal
Odd-looking
Oddball
Off-key
Off-kilter
Officiary
Offline
Ogreish
Okay
Old hat
Old-school
Old-world
Older
Oldest
Oncological
One-legged
One-sided
Overassertive
Overvaliant
Obliged
Observed
Obviating
Offenceless
Offending
Offsides
Opened
Operationalist
Opportunist
Oppressed
Orchestrated
Orientating
Orienting
Orthodontic
Orthographic
Oscillating
Oscillatory
Osmotic
Outdoorsy
Outfitted
Outlined
Outsize
Overage
Overawed
Overdone
Overeager
Overflowing
Overloaded
Overlooked
Overreaching
Overriding
Overstated
Overturned
Ovular
Oxalic

Adjectives that Start with O to Describe a Person

Observant – quick to notice things and pay attention to details
Optimistic – having a positive outlook on life and expecting good things to happen
Outgoing – friendly, sociable, and extroverted
Open-minded – willing to consider different viewpoints and ideas
Organized – having a structured and orderly approach to tasks and activities
Original – unique and creative, not derivative or copied from others
Objective – impartial and unbiased, not influenced by personal feelings or opinions
Obliging – willing to help and be of service to others
Outstanding – exceptional and impressive, standing out from others in a positive way
Observational – keenly aware and perceptive, often associated with writers or artists
Obsequious – overly eager to please and overly deferential to authority figures
Overconfident – excessively self-assured and confident, often to the point of arrogance
Opinionated – holding strong and often inflexible opinions, often at the expense of considering other viewpoints
Overbearing – domineering and controlling, often in an oppressive or unpleasant way
Obedient – willing to follow rules and authority without question
Offensive – causing offense or hurt feelings, often due to insensitive or inappropriate behavior
Ostentatious – showy and attention-seeking, often associated with excessive wealth or status
Overprotective – excessively concerned with the safety and well-being of others, often to the point of being overbearing
Outspoken – frank and direct in expressing opinions and ideas, often without concern for social conventions or politeness
Overwhelmed – feeling overwhelmed or stressed by a situation or task that seems too difficult to handle.

Adjectives that Start with O to Describe Food

Organic – grown without the use of pesticides or other chemicals
Oily – containing a high amount of oil or fat
Overcooked – cooked for too long, resulting in a dry or tough texture
Overripe – too ripe, often resulting in a mushy or unappetizing texture
Oven-baked – cooked in an oven, often resulting in a crispy or browned texture
Odorous – having a strong or unpleasant smell
On-the-go – designed for easy consumption while on the move, often used to describe snacks or convenience foods
Outrageous – unusually large or excessive in size, often used to describe portions or servings
Overwhelming – having a strong or intense flavor, often used to describe spices or seasonings
Organic-certified – meeting the strict standards for organic certification, often used to describe produce or dairy products
Off-flavor – having an unpleasant or unusual flavor, often due to spoilage or contamination
Oven-roasted – cooked in an oven, often resulting in a tender and flavorful texture
Open-flame-grilled – cooked over an open flame, often resulting in a smoky and charred flavor
Organic-fed – raised on organic feed, often used to describe meat or poultry products
Oven-ready – prepared and ready to be cooked in an oven, often used to describe pre-packaged meals or ingredients
Oozing – having a soft and melting texture, often used to describe cheese or chocolate

Adjectives that Start with O to Describe a Place

Open – not enclosed or blocked, often associated with spaciousness and freedom
Old-fashioned – traditional or classic in style or design, often associated with historical or cultural significance
Ornate – highly decorated or embellished, often associated with grandeur and luxury
Oceanfront – located along the ocean, often associated with scenic views and waterfront activities
Overcrowded – having too many people or objects in a limited space, often associated with congestion and discomfort
Off-the-beaten-path – located in a less-traveled or less-frequented area, often associated with hidden gems and unique experiences
Opaque – not transparent or clear, often associated with mystery and obscurity
Outdoor – located outside, often associated with nature and outdoor activities
Open-air – not enclosed or covered, often associated with fresh air and natural light
Overgrown – covered or filled with overgrown vegetation, often associated with neglect and abandonment
Outlying – located far from the center or main area, often associated with rural or remote areas
Overlooking – situated above and with a view of, often associated with scenic views and privacy
Overwhelming – having a powerful and intense impact, often associated with awe and amazement
Old-world – traditional or classic in style or design, often associated with historical or cultural significance
Opulent – luxurious and grand, often associated with wealth and extravagance
Outdoorsy – suited to outdoor activities and pursuits, often associated with adventure and exploration
Organic – free from artificial additives or chemicals, often associated with natural and healthy living
Open-plan – lacking walls or partitions, often associated with modern and flexible living spaces
Orderly – neat and well-organized, often associated with efficiency and professionalism
Oasis-like – resembling an oasis, often associated with a peaceful and refreshing environment.

Adjectives that Start with O to Describe Feelings and Emotions

Optimistic – having a positive outlook on life and expecting good things to happen
Overwhelmed – feeling overwhelmed or stressed by a situation or task that seems too difficult to handle
Offended – feeling hurt or insulted by someone’s words or actions
Overjoyed – extremely happy and joyful
Outraged – feeling angry or indignant about something that is perceived as unjust or wrong
Obliged – feeling a sense of duty or responsibility towards someone or something
Overcome – feeling overwhelmed or defeated by something, often associated with a sense of powerlessness
Obsessed – having an intense and consuming preoccupation with something, often to the point of being unhealthy
Open-hearted – being open and sincere in expressing emotions and feelings, often associated with warmth and generosity
Over-sensitive – easily hurt or offended by criticism or negative feedback

Adjectives that Start with O with Examples

Obvious – It was obvious that he was lying.
Obedient – The obedient dog always followed its owner’s commands.
Odd – That’s an odd way to do things.
Old – The old man lived alone in a small house.
Open – The open window let in a cool breeze.
Optimistic – She had an optimistic outlook on life.
Original – The painting was an original by a famous artist.
Outrageous – The price of the car was outrageous.
Outstanding – His performance was outstanding and he received a standing ovation.
Overwhelming – The amount of work was overwhelming.
Ordinary – The food was just ordinary, nothing special.
Organic – The organic vegetables were grown without pesticides.
Ornate – The ornate decoration on the building was beautiful.
Opaque – The glass was opaque and you couldn’t see through it.
Onerous – The task of cleaning the entire house was onerous.
Offensive – His comments were offensive and hurtful.
Observant – The observant detective noticed a clue that others had missed.
Open-minded – She was open-minded and willing to consider different viewpoints.
Opportunistic – The politician was accused of being opportunistic and only interested in gaining power.
Overdue – The bill was overdue and needed to be paid immediately.

Learn more with words that start with O in English.

Adjectives that Start with O Infographic

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