FMUBD Share definition Flag Like FMUD, this an abbreviation for “Fill me up black daddy!!!” It also can be used in past tense. Was fucking this fat white chick and she yelled out FMUBD, and I came so hard it shot out her nose. FMUBD by kgriffin033 February 17, 2018 0 0 Get merch Get the FMUBD mug. Buy Now — $32.95 See more merch