bloody knuckle Share definition Flag When 2 girls are each on their period and scissor each other. Jen and Pam were both on the rag, and horned up for eachother, so they got into scissor position and bumped the bloody knuckle. bloody knuckle by KNuckle PUck April 24, 2010 0 0 Get merch Get the bloody knuckle mug. Buy Now — $32.95 See more merch