WordWeb Online

1. Show one's unhappiness or critical attitude
   "We grumbled about the increased work load";
   - grouch, scold, moan
    
2. Make complaining remarks or noises under one's breath
   "she grumbles when she feels overworked";
   - murmur, mutter, croak, gnarl [archaic], chunter [Brit, informal]
    
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

1. A loud low dull continuous noise
   - rumble, rumbling, grumbling
    
2. A complaint uttered in a low and indistinct tone
   - grumbling, murmur, murmuring, mutter, muttering

Derived forms: grumbles, grumbled, grumbling

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