Definition from Wiktionary, the free dictionary
- One who is given to obnoxious or insolent humor; a wise guy.
- One who is pretentious about their own cleverness or knowledge; a know-it-all.
- One who is obnoxiously self-assured; a show off.
- (rare) A well-dressed person.
- (someone who makes insolent or obnoxious jokes): smarty, smarty pants, wise guy, wise apple
- (someone who is pretentious about their own cleverness): know-it-all, (UK) clever dick, smart ass, smarty pants, wiseacre
- (someone who is obnoxiously self-assured): smart ass
- smart-aleck (adjective)