a wise guy

(American & Australian informal) also a wise-ass (American very informal!)

someone who is always trying to seem more clever than everyone else in a way that is annoying Okay, wise guy, if you're so damned smart, you can tell everyone how it's done! He's just some wise-ass who thinks he knows all the answers. (American & Australian informal)

See an old head on young shoulders

Common Names:

Name	Pronounced	Usage
Melia	-	Greek Mythology
Levente	-	Hungarian
Alkaios	-	Ancient Greek
Drazhan	-	Medieval Slavic
Agnese	ah-NYE-ze (Italian), AHG-ne-se (Latvian)	Italian, Latvian
Borut	-	Slovene