F-blanket Share definition Flag Short for a fuck blanket. Usually referred to a female that is used by one or many guys for sex. The girl is never considered a girlfriend or respected. Who's that girl? Oh, that's Bobby's new f-blanket. F-blanket by 711Arbor May 8, 2009 0 0 Get merch Get the F-blanket mug. Buy Now — $32.95 See more merch