Some one who can'tthink for them selves or otherwise thought as stupid.
Will robertson is a dumbass for thinking he's not hipster. When someone turns into a zombie why do they turn into a dumbass? "Why are Brad and Angelina together? I think their a bunch of dumbasses"
A guy who pays real money for a lawyerto go to a courtroom in the guise of a trial.
The dumbass is really gonna get a lawyer to go to court. Even though it was a prank, he's a dumbass for paying the lawyer and the medical bills he got, hahahahaha that's hilarious and awesome.