FTL Share definition Flag fuck(ing) the lions; used as reference to lions/cougars particularly in night clubs Bob- "Dude, I was totally FTL last night." Bill- "Omg. No way, you're nuts, bro. FTL by idkmybffjilll January 22, 2012 0 0 Get merch Get the FTL mug. Buy Now — $32.95 See more merch