late 14c., "make a deep, heavy, continuous sound," also "move with a rolling, thundering sound," also "create disorder and confusion," probably related to Middle Dutch rommelen "to rumble," Middle High German rummeln, Old Norse rymja "to shout, roar," all of imitative origin. Slang sense of "engage in a gang-fight" is by 1959. Related: Rumbled; rumbling.
"a deep, heavy, continuous rattling or dully roaring sound," as of thunder, late 14c., from rumble (v.). From 14c. to 17c. it also meant "confusion, disorder, tumult." The slang noun meaning "gang fight" is by 1946. The meaning "backmost part of a carriage" (typically reserved for servants or luggage) is from 1808 (earlier rumbler, 1801), probably from the effect of sitting over the wheels; hence rumble seat (1828), later transferred to automobiles.