Grumbles rhymes with:
crumbles, rumbles, crumbles, fumbles, humbles, mumbles, rumbles, stumbles, tumbles, ambles, assembles, brambles, campbell's, campbells, crumbles, cymbals, ensembles, fumbles, gamble's, gambles, humbles, kimball's, mumbles, resembles, rumbles, scrambles, shambles, stumbles, symbol's, symbols, tumbles, wombles