Grumble rhymes with:
crumble, rumble, trumble, trumbull, bumble, crumble, fumble, gumbel, humble, jumble, kumble, mumble, rumble, stumble, trumble, trumbull, tumble, umbel, umble
Grumble sounds like:
gorenflo, granville, greenfell, greenvale, greenville, grenfell, grenoble, guerneville