A derogatory slang term for a specific type of metal head that is extremely elitist, is rarely seen in places other than the internet, listens to doom metal, plays Dungeons and Dragons, World of Warcraft or engages in some other type of nerdy activity. A dumbis is usually fat and will dress in cargo shorts, skate shoes, and an Isis shirt. Dumbi rarely have long hair like other metal heads, instead opting for a long neck beard or slightly "shaggy" hair.
Comedian and actor Brian Posehn is a dumbis.
by BroUpBroDown February 08, 2011
Someone, usually a friend, who does something unbelievably betraying or idiotic. Strong way of saying, "dummy."
Joe: You told Christine my deep, dark secret? You dumbi!!!
by Marzipanesque May 20, 2007
a slang term for a specific type of metal head, that is usually fat, nerdy and wears cargo shorts. Dumbi generally listen to sludge metal, and are very pretentious. They'll talk your ear off about Dungeons and Dragons too.
Comedian Brian Posehn is a huge dumbis.
by blackmetaldumbis February 16, 2011
One who is dumber than usual.
John is such a Dumbis, he lost his keys to his car.
by Scott Warshire August 15, 2007