nounDum-Derty - A person who is dumb and dirty at the same time. It makes saying it faster, condensing it into one word. Instead of saying, "wow that was dumb and dirty at the same time" you can now say, "DUMBDIRTY"
Chad: Your so uglyyyy
Carmen: wow just shut up
Matt, Pete,Jan: That was just DUMBDIRTY.
Carmen: Ohh my god....