A person who is both dumb and an ass at the same time. Contrast with "dumbass," which is a conjugate of the terms, thereby creating a new class of person. However, "dumb ass" confers a meaning by which a person is both embarassing to the human race and of below average intelligence.
Everyone's right: George W. Bush is a complete, 100%, genuine, Grade-A Dumb-Ass!!
He's the perfect example!! No better definition than that!!!
I've neverseen a bigger Dumb-Ass than our very own President George W. "Dumb-Ass" Bush!!
If you voted for him, shame on you!!