forming words, with the meanings:
out or forth
obtrude
offer
exposed
obverse
so as to involve compliance
obey
observe
against or in opposition to
obloquy
opponent
resisting
obstinate
in the way of; hindering
obstacle
obstruct
hidden or concealed
obfuscatory
occult
inversely
obovate
[Middle English via Old French from Latin ob in the way of, on account of]