fubster Share definition Flag A guy who tells girls to "Fire Up Bitch" The Fubster is the rugby player in the Dragons (NRL Australia) who sent texts to a fat mole telling her "Fire Up Bitch" fubster by LivS2Fubster September 21, 2006 0 0 Get merch Get the fubster mug. Buy Now — $32.95 See more merch