Spider Butt Share definition Flag A girl's butt which appears large or shaped like a spider's rear end. Looks like the abdomen (butt) of a spider John: That girl has a huge ass! Edwin: yeah, that's a spider butt. Spider Butt by Charlie Cash January 20, 2009 0 0 Get merch Get the Spider Butt mug. Buy Now — $32.95 See more merch