A person sho exhibits all the tendecies of an asshole and a jackass. The unique combination of being obnoxious, (asshole), and completely obtuse or insensitive (jackass) requires it's own insult.
A person whose behavior resembles both a jackass and an a****** at the same time. Often used as a term of endearment or to address someone you are typically fond of.
"Stop being a jackhole or you're going to embarrass yourself."