www.alphadictionary.com

This appears to be strictly a Germanic word. Both a noun and a verb. It means move with a rolling, thunderous sound. Think also of rumble seat, so called because it was directly over the wheels and that is where it was felt the most. But the I was thinking about the number of words that rhyme with rumble and carry the same sense: stumble, mumble, rumble, crumble, bumble, fumble.

Isn’t there a word for groups of words like that? Slush, mush, flush, gush…