INCOMPOSSIBLE, adj. Unable to exist if something else exists. Two
things are incompossible when the world of being has scope enough for
one of them, but not enough for both -- as Walt Whitman's poetry and
God's mercy to man. Incompossibility, it will be seen, is only
incompatibility let loose. Instead of such low language as "Go heel
yourself -- I mean to kill you on sight," the words, "Sir, we are
incompossible," would convey and equally significant intimation and in
stately courtesy are altogether superior.
-- Ambrose Bierce, "The Devil's Dictionary"
OBSOLETE, adj. No longer used by the timid. Said chiefly of words.
A word which some lexicographer has marked obsolete is ever thereafter
an object of dread and loathing to the fool writer, but if it is a
good word and has no exact modern equivalent equally good, it is good
enough for the good writer....