DMWEL (pronouced dim-well)

Dumbest
Muthafucker
Who
Ever
Lived

(From a line in Tropic Thunder)

DMWEL (pronouced dim-well)

You get cut off in traffic, shake your fist and shout "DMWEL!"
Waiter bring you the wrong order then rolls his eyes when you say something? He's a DMWEL. Best friend get back with the cheating ex? DMWEL!

Really, a thousand and one uses!!!!