wise guy

Short definition from Wiktionary

Noun

1. 1
   One who is insolent or flippant; one who makes jokes or perpetrates pranks.
2. 2
   A knowledgeable or successful sports bettor.
3. 3
   A member of the Mafia; a mobster.
4. 4
   A hipster.
5. 5
   An Italian-American man.
6. 6
   Alternative spelling of wiseguy.