(v.) One who makes undue pretensions to wisdom; a would-be-wise person; hence, in contempt, a simpleton; a dunce.
Example Sentences:
(1) For too long, Chris Bosh has been attacked as soft, in often borderline sexist terms, by everyone from Shaquille O'Neal (who memorably called him "the RuPaul of big men" back in his actually amusing pre-analyst days) to wiseacres on Twitter .
(2) Another wiseacre has convinced himself that making people laugh is exerting some kind of power over them.
(3) (The wiseacres on Twitter suggested an alternate theory: Bryant just didn't want to be stuck in the locker room with Howard for the rest of the game and, quite frankly, who could blame him?)
(4) Dane DeHaan, John C Reilly, Molly Shannon and a lot of other people you recognize co-star in this story of a wiseacre girl who becomes a zombie.