- obstinate show of strength
- obstinance
- obdurate
- occlusion
- observe
- obey
- one hundred
- one c
- obstetrical delivery
- organism
- orator
- overhaul
- orchidaceous plant
- orchid
- operation
- occupy
- one thousand
- organophosphate nerve agent
- olive drab
- oilcloth
- organza
- oppose
- office
- ointment
- oṉe who deserves being granted alms
- ordure
- obsolete
- overclothes
- outerwear
- one
- old salt
- opaline
- opalescent
- old colony
- oilskin
- oleoresin
- occlusive
- organ pipe
- oxygen
- overcup oak
- ob
- oates
- oarlock
- oat
- oast house
- oath
- oatmeal
- oath of secrecy
- obadiah
- obduracy