A form of the more common Failure
combined with an Ass Hole
. Basically a combination of the worst traits of both: the mental, social, and physical shortcomings of a Failure, with all the obnoxious douchebaggery of an Ass Hole.
1. Joel may be a Failure, but at least he's not an Ass Clown...
2. Shawn is indeed an Ass Clown