KP Line Share definition Flag A sick line of ket (K) and crushed up pill/mdma (P) guaranteed to get you fuuucked! We snorted a few KP lines last night after the club and got absolutely trollied! KP Line by MEGADEATHrave October 21, 2008 0 0 Get merch Get the KP Line mug. Buy Now — $32.95 See more merch