rumbling

adj

1. Deep- and slow-sounding.

   “rumbling discontent”

   “His rumbling voice suited the solemn occasion.”

   “rumbling stomachs”

noun

1. A muted sound of complaint or discontent (often used in the plural).

   “The rumblings of the masses precede the crumbling of the state.”

2. A deep low noise.

   “The rumbling of distant thunder echoed from the hilltop.”

   “The rumblin' from distant shores sends me to sleep / But the facts of life can sometimes make it hard to dream”

verb

1. (form-of, gerund, participle, present)present participle and gerund of rumble