the GNU version of the Collaborative International Dictionary of English
a. & n. from rumble, v. i.
The Century Dictionary and Cyclopedia
n. A low, heavy, continued rattling or jarring sound; a rumble. The peculiar rumbling of the bowels is technically called borborygmus.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. continuous full and low-pitched throbbing sound
n. a loud low dull continuous noise
Word Usage
"That left behind 97% of what they call the rumbling radioactive volcano including something like 216 tons of highly radioactive graphite and uranium."