Gumblegasm Share definition Flag The act of cumming in your hand then rubbing it into a homeless man's eyes. I was out with the boys the other night and we decided to go out and hunt down some bums for a couple of Gumblegasms Gumblegasm by SlapMeSideways February 10, 2019 0 0 Get merch Get the Gumblegasm mug. Buy Now — $32.95 See more merch