wiseacre
One who feigns knowledge or cleverness; one who is wisecracking; an insolent upstart.
That other class of wiseacres who twist prophecy in such a manner as to make it promise the destruction and desolation of the same city, use judgement just as bad, since the city is in a very flourishing condition now, unhappily for them.
A learned or wise man.
obsolete
A fool's paradise is better than a wiseacre's purgatory.
Where it comes from
From Middle Dutch wijssegger (“soothsayer”), from Old High German wīzzago, wīzago (“wise man, prophet, soothsayer”), from Proto-West Germanic *wītagō (“wise one; prophet”). Cognate with Old English wītga (“wise man, prophet”). See also German Weissager (“soothsayer, seer”).
Adapted from the Wiktionary entry wiseacre (CC BY-SA 4.0).