grumbling

adj 1: continuous full and low-pitched throbbing sound; "the

rumbling rolling sound of thunder" [syn: {rumbling}]

2: muttering discontentedly; "the grumbling boarders requested

a meeting with the cook"

n 1: a loud low dull continuous noise; "they heard the rumbling

of thunder" [syn: {rumble}, {rumbling}, {grumble}]

2: a complaint uttered in a low and indistinct tone [syn: {grumble},

{murmur}, {murmuring}, {mutter}, {muttering}]