GRUMBLE

Definition of GRUMBLE

  1. (verb)show one's unhappiness or critical attitude
  2. (verb)make complaining remarks or noises under one's breath
  3. (verb)to utter or emit low dull rumbling sounds
  4. (verb)make a low noise
  5. (noun)a loud low dull continuous noise
  6. (noun)a complaint uttered in a low and indistinct tone