Term used to define a goomba's testicles in a Super Mario game. Can also be used to describe opponents in a Nintendo game that features Mario, or to describe related characters, even including females, such as Peach, Daisy, etc.
1: "Time to kick some goomballs in New Super Mario Bros!"
2: "Finally, I kicked Bowser's goomballs once and for all!"
3: "Look out NOA Dave, I'm about to bust your goomballs in Mario Kart DS!"