flumble Share definition Flag A flying-tumbling motion, esp. as a covenant soldier from the original Halo. "It has been show that, post fragmentation, grenades commonly cause grunts, and occasionally even elites, to flumble hilariously." flumble by Captain Dingleberry June 10, 2009 0 0 Get merch Get the flumble mug. Buy Now — $32.95 See more merch