cumberbun Share definition Flag Verbto cumberbun; cumberbunned, cumberbunning1. The act of shoving a cucumber up someone's ass. "I'm gonna take your grandma upstairs and cumberbun her." cumberbun by billebllunt September 25, 2014 0 0 Get merch Get the cumberbun mug. Buy Now — $32.95 See more merch