rumbling (Adjective) — Continuous full and low-pitched throbbing sound. ex. "the rumbling rolling sound of thunder"
rumbling (Noun) — A loud low dull continuous noise. ex. "they heard the rumbling of thunder"
rumbling (Verb) — Make a low noise. ex. "rumbling thunder"
rumbling (Verb) — To utter or emit low dull rumbling sounds. ex. "he rumbled a rude response"
rumbling (Verb) — Uncover a deceit or secret activity.