Knee-pussy Share definition Flag The spot on the back of your leg where the knee bends. When bent, it stands as an acceptable substitute for an actual vagina. I didn't get laid tonight, so when I got home I fucked my passed-out roommate's knee-pussy. Knee-pussy by Strangehunters July 7, 2009 0 0 Get merch Get the Knee-pussy mug. Buy Now — $32.95 See more merch