assclown

noun2

1. •
   (slang, vulgar) A jerk; a buffoon; a person who is inept or ill-behaved to the point of being found laughable by others.
2. •
   (slang, vulgar) A jerk; a buffoon; a person who uses their nature to bring humor to others, but ends up being the butt of a joke.

   • I'm a little loaded, and this assclown behind me has bumped me four times in a row. — 2006