Definition of rumbles:
(n) :
A low, heavy, continuous sound, such as that of thunder or a hungry stomach.
(v) :
(intransitive) To make a low, heavy, continuous sound.
(v) :
(intransitive) To move while making a rumbling noise.
(n) :
(slang) A street fight or brawl.
(v) :
(slang, intransitive) To fight; to brawl.
(n) :
A rotating cask or box in which small articles are smoothed or polished by friction against each other.