[verb] show one's unhappiness or critical attitude; "He scolded about anything that he thought was wrong"; "We grumbled about the increased work load" Synonyms:grouch, scold
[verb] make complaining remarks or noises under one's breath; "she grumbles when she feels overworked" Synonyms:murmur, mutter, croak, gnarl
[verb] to utter or emit low dull rumbling sounds; "he grumbled a rude response"; "Stones grumbled down the cliff" Synonyms:growl, rumble
[verb] make a low noise; "rumbling thunder" Synonyms:rumble
