rumbling
1. [ adjective ] continuous full and low-pitched throbbing sound
Synonyms: grumbling
Examples:

"the rumbling rolling sound of thunder"

Related terms: full
2. [ noun ] a loud low dull continuous noise
Synonyms: rumble grumbling grumble
Examples:

"they heard the rumbling of thunder"

Related terms: noise borborygmus grumble rumble
Similar spelling:   rambling
  ramblingly
  rumble
  Rumbley