ten-knuckle buckle Share definition Flag A slang term used to describe the act of double fisting. I'm still sore from last night. your mom pulled out the ten-knuckle buckle on my ass! ten-knuckle buckle by tamara p.s. October 28, 2007 0 0 Get merch Get the ten-knuckle buckle mug. Buy Now — $32.95 See more merch