1 definition by DarthSlymer

An acronym for the phrase, Goofy Ugly Mother Fucker. The word is used when it would be innapropriate to say, "Goofy, Ugly, Mother Fucker" aloud.
Dave: "Oh my god, look at that GUMF over there!"
Chris:"Shit's hurtin' my eyes! Lets get out of here!"
by DarthSlymer July 13, 2011
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