grumbles

Noun

• a loud low dull continuous noise
• a complaint uttered in a low and indistinct tone
• plural of grumble

Verb

• show one's unhappiness or critical attitude
• make complaining remarks or noises under one's breath
  • "she grumbles when she feels overworked"
• to utter or emit low dull rumbling sounds
• make a low noise
• third-person singular simple present indicative of grumble

Synonyms

croak, gnarl, grouch, growl, grumble, grumbling, murmur, murmuring, mutter, muttering, rumble, rumbling, scold