GRE Vocabs Os
obdurate
obeisance
obfuscated
objectionable
objective
objurgation
obloquy
obsequious
obstinate
obstreperous
obtrusive
occluded
odious
officious
offset
ogle
omission
omniscient
onus
opaque
openhanded
opine
opportune
opprobrium
opulent
ornate
orthodox
oscillate
ossified
ostentatious
ostracized
otiose
outmoded
outstrip
overshadow
overweening