GAPKAP Share definition Flag Grow A Pair, Keep A Pair. Used for when you are telling someone to stand up for something. "Cindy wants me to go to the opera with her but I don't want to." "GAPKAP dude." GAPKAP by popnlochnessmonster February 22, 2009 0 0 Get merch Get the GAPKAP mug. Buy Now — $32.95 See more merch