fmugly Share definition Flag A description of an extremly ugly person or thing. Means fucking mega ugly. An even stronger term is "Mfugly" meaning mega fucking ugly. man, look over there at that "fmugly" muppet fmugly by widgetkiwi June 21, 2007 0 0 Get merch Get the fmugly mug. Buy Now — $32.95 See more merch