nugatory
trifling; invalid (unbedeutend)
obdurate
stubborn (dickköpfig)
obsequious
overly submissive
obsequy
funeral ceremony (often used in plural)
obviate
to make unnecessary; to anticipate and prevent
occlude
to shut; Block
occult
relating to practices connected with supernatural phenomena
odyssey
a long, adventurous voyage; a quest
officious
too helpful; meddlesome
olfactory
concerning the sense of smell