bust a grub Share definition Flag To bust a grub: To eat, scarf as if you were at the buffet. Dude, I went to go and bust a grub at the Denny's but the waitress ruined my apetite she was a torebacula! (See torebacula) bust a grub by Maia A February 15, 2007 0 0 Get merch Get the bust a grub mug. Buy Now — $32.95 See more merch