KFR Share definition Flag Kick Fucking RocksUsed when trying to get rid of losers in your life. In a text message bitching about your gf that sticks with her loser bf: "If my boyfriend cheated on me I'd tell him to KFR!" KFR by NonieM December 15, 2011 0 0 Get merch Get the KFR mug. Buy Now — $32.95 See more merch