Gubble Share definition Flag The lower, protruding mandible on a canine with an under-bite, evident in such breeds as Bulldogs, Pugs, Boxers and Mastiffs. "He's got his nubble stuck in his gubble!" "Put your gubble in..." Gubble by idiot_legs December 22, 2008 0 0 Get merch Get the Gubble mug. Buy Now — $32.95 See more merch