- obdurate
- obeisance
- obesity
- obfuscate
- objurgate
- obliterate
- obloquy
- obnoxious
- obscure
- obsequious
- obsolescent
- odious
- officious
- olfactory
- ominous
- omniscient
- opalescent
- opaque
- operative
- opprobrious
- ordain
- ornithologist
- orotund
- ostentatious
- ostracize
- otiose
- overweening
成人英语GMAT800分常考单词单词大全〔O 〕课程包含27个英语单词词汇。