smarty pants(redirected from a smarty pants)
1. One who obnoxiously and frequently attempts to assert perceived superiority in intelligence; a know-it-all. Don't be such a smarty pants. You don't know everything.
2. One who makes jokes and uses sarcasm in an attempt to seem witty, but instead is deemed annoying; a smart aleck. OK, smarty pants, are you going to help me, or just stand there mocking me all night?
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
n. a cocky person; a smart aleck. Look, smarty-pants, let’s cut the clowning around.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.