in phrase in the offing, 1779, from nautical term offing "the more distant part of the sea as seen from the shore" (1620s), from off (q.v.) + noun suffix -ing (1). Originally the phrase meant "in the distant future;" modern sense of "impending" developed 1914.
officialese
officiant
officiate
officinal
officious
offing
off-key
off-limits
off-line
off-load
off-peak