- objet d'art
- oblanceolate leaf
- oblateness
- oblation of cooked rice to the manes
- obligatory
- oblige
- obliged
- obliged by
- obliger
- obliging
- obligingly
- oblique bandage
- oblique case
- oblique form
- oblique remark
- oblique singular form of
- oblique speech
- obliquely
- obliquity
- obliterable
- obliterate
- oblivion
- obliterated
- obliteration
- oblivious
- oblong
- oblong woodsia
- oblongness
- oboe d'amore
- oboe da caccia
- obscence
- obscene
- obscenely
- obscurantism
- obscuratism
- obscurantist
- obscureness
- obsequians
- oasis
- oat cell carcinoma
- oat meal
- oarsman
- oatmeal cookie
- oaxaca
- oats
- obdurately
- obedient servant
- obedience plant
- obe
- obedient