jackass

Short definition from Wiktionary

Noun

1. 1
   A male donkey.
2. 2
   A foolish or stupid person.
3. 3
   An inappropriately rude or obnoxious person.
4. 4
   A kind of bootleg liquor.
5. 5
   The laughing kookaburra.
6. 6
   A jack and an ace as a starting hand in Texas hold 'em.

Verb

1. 1
   To behave very obnoxiously.