1. (Doo-MAHS) An altered pronunciation of "dumbass", invested with faux-French cachet. See also Targeé
2. A fool of epic proportion; oaf, nincompoop; a personage of supreme incompetence and/or stupidity.
3. The celebrated French author Alexandre Dumas (The Count of Monte Cristo).
"Did you hear that Pierre got arrested last night for getting trashed and trying to climb the Eiffel tower in his underpants??? What a Dumbass!"
"Yeah, dude. He's totally a Dumas."
"Yeah. Awesome though."