stfuumfcs Share definition Flag A very short way of saying, "Shut the fuck up you mother fucking cock sucker" RUNN: hey SolariSin: STFUUMFCS!!!!111OEN!!!11 stfuumfcs by SolariSin February 10, 2004 0 0 Get merch Get the stfuumfcs mug. Buy Now — $32.95 See more merch