Grumbling has 5 different meanings across 2 categories:
Noun
· Adjective
Noun
1
a loud low dull continuous noise
"they heard the rumbling of thunder"
2
a complaint uttered in a low and indistinct tone
Verb
1
present participle of grumble
Adjective
1
continuous full and low-pitched throbbing sound
"the rumbling rolling sound of thunder"
Broader Terms (hypernyms)