Collins English Dictionary: English Words Starting With “O”
- -o ... oak processionary moth
- oak-aged ... oater
- Oates ... obeism
- obeli ... object linking and embedding
- object of virtu ... oblate
- oblately ... obliviousness
- obliviscence ... obscurum per obscurius
- obsecrate ... obsidional
- obsidionary ... obstruent
- obtain ... Obwalden
- OC ... occupancies
- occupancy ... oceanic trench
- Oceanid ... Ockenheim
- ocker ... octapodic
- octapody ... octopusher
- octoroon ... oddball
- Oddfellow ... odontalgy
- odontic ... odyle
- odylism ... Oerlikon
- oersted ... off and on
- off base ... off-beam
- off-Broadway ... Offenbach
- offence ... officer
- officer of arms ... offshoot
- offshore ... Ogpu
- ogre ... oil installation
- oil lamp ... oilfired
- oilgas ... Okie
- okimono ... Old Frisian
- old fustic ... Old Stone Age
- old style ... oldwives
- -ole ... olfactory nerve
- olfactory tract ... oliguria
- Ólimbos ... Olympiad
- Olympian ... omenta
- omental ... omniform
- omniformity ... on a bowline
- on a jar ... on ice
- on impulse ... on schedule
- on seat ... on the face of it
- on the fence ... on the ropes
- on the run ... on view
- on welfare ... oncogenicity
- oncogenous ... one's hour
- one's lane ... one-stop shop
- one-stop shopping ... onion johnny
- onion ring ... onshore
- onshoring ... oocyst
- oocyte ... oosperm
- oosphere ... opeidoscope
- open ... open up
- open verdict ... opening times
- openly ... Operation Desert Storm
- Operation Overlord ... ophiolitic
- ophiologic ... opinionatedly
- opinionatedness ... oppo
- opponency ... oppugn
- oppugnancy ... optical disk
- optical double star ... optoelectronic
- optoelectronics ... oral
- oral eroticism ... Orangewomen
- orangewood ... orchesography
- orchestic ... order number
- Order of Australia ... ordination
- ordinee ... org
- org. ... organization man
- organization men ... orgiastic
- orgiastically ... origanum
- Origen ... Ormazd
- ormer ... ornithosis
- oro- ... Orr
- orra ... orthodromic
- orthodromy ... orthopedic surgery
- orthopedical ... orthotropic
- orthotropism ... oscillatory
- oscillogram ... osmeterium
- osmic ... ossiferous
- ossific ... osteofibrosis
- osteogen ... ostler
- ostleress ... otary
- OTB ... otosclerosis
- otoscope ... ouistiti
- Oujda ... out of phase
- out of pocket ... out-of-sight
- out-of-state ... outbeam
- outbeg ... outcome
- outcompete ... outdwell
- outearn ... outgassed
- outgassing ... outjuggle
- outjump ... outman
- outmaneuver ... outpost
- outpour ... outrigging
- outright ... outside-left
- outside-right ... outstay
- outstay one's welcome ... outward journey
- outward-looking ... ovarial
- ovarian ... over-aged
- over-alert ... overattentive
- overawe ... overbrow
- overbrowse ... overcloud
- overcloy ... overcrowding
- overcultivation ... overdriven
- overdriving ... overexcited
- overexcitement ... overflowingly
- overflown ... overgrain
- overgrainer ... overhomogenise
- overhomogenize ... overlander
- overlap ... overmatch
- overmatter ... overpack
- overpage ... overpriced
- overprint ... overrife
- overrigid ... oversexed
- overshade ... overspill town
- overspilt ... oversupplies
- oversupply ... overtly
- overtness ... overweigh
- overweight ... oviposition
- ovipositional ... own goal
- own label ... Oxford frame
- Oxford Group ... oxtail soup
- oxter ... oxysome
- oxysulphide ... ozone depletion
- ozone hole ... ozzie