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.
John you are not only a dumbass, you are a DUMB ASS.
(n.) someone who is unbelieveably stupid or does stupid things.
Ryan, you are such a dumb ass for playing baseball with broken bones.
You are a dumb ass for not knowing what the word dumb ass means.
the people who think anything on the urban dictionary is true
everyone who resides in the urbandictionary chat rooms asking for pics and if you want to cyber.
"Hey. asl? pics? webcam?"
"You are such a dumb ass..."