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515 Best Adjectives that Start with O | O Adjectives

515 Best Adjectives that Start with O | O Adjectives

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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.

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

Adjectives that Start with O: List of 100+ Adjectives Starting with O in English