volatile: The political climate today is extremely volatile: no one can predict what the electorate will do next. Maria Callas's temper was extremely volatile: the only thing you could predict was that she was sure to blow up. Acetone is an extremely volatile liquid: it evaporates instantly.
ADJ. changeable; explosive; evaporating rapidly.
voluble: The excessively voluble speaker suffers from logorrhea: he runs off at the mouth a lot!
ADJ. fluent; glib; talkative.
whimsical: In Mrs. Doubtfire the hero is a playful, whimsical man who takes a notion to dress up as a woman so that he can look after his children, who are in the custody of his ex-wife. whimsy, N.
ADJ. capricious; fanciful.
witticism: I don't mean any criticism, but that last witticism totally hurt my feelings
N. witty saying. wisecrack.
zealot: Though Glenn was devout, he was no zealot; he never tried to force his beliefs on his friends.