gigabutt Share definition Flag A shapely, prominent butt. Similar to badonkadonk but more for the nerdy crowd. (In meeting, silently to guy next to you) "Check out the presenter's gigabutt. That's a nice jiggle." gigabutt by almuric January 27, 2013 0 0 Get merch Get the gigabutt mug. Buy Now — $32.95 See more merch