1. Continuous full and low-pitched throbbing sound
   "the grumbling rolling sound of thunder";
   - rumbling

1. A loud low dull continuous noise
   "they heard the grumbling of thunder";
   - rumble, rumbling, grumble
    
2. A complaint uttered in a low and indistinct tone
   "I could hear his constant grumbling about the new policy";
   - grumble, murmur, murmuring, mutter, muttering

1. Make complaining remarks or noises under one's breath
   "she grumbles when she feels overworked";
   - murmur, mutter, croak, gnarl [archaic], chunter [Brit, informal]
    
2. Show one's unhappiness or critical attitude
   "We grumbled about the increased work load";
   - grouch, scold, moan
    
3. To utter or emit low dull rumbling sounds
   "he grumbled a rude response"; "Stones grumbled down the cliff";
   - growl, rumble
    
4. Make a low noise
   "grumbling thunder";
   - rumble

Derived forms: grumblings

See also: full

Type of: complain, complaint, emit, go, kick [informal], kvetch [N. Amer, informal], let loose, let out, moan, noise, plain [archaic], sound, sound off, utter

Encyclopedia: Grumble