Definitions:

1. make complaining remarks or noises under one's breath verb
   • They grumble when they feel overworked.
2. to utter or emit low dull rumbling sounds verb
   • I grumbled a rude response into my drink.

Synonyms:

• grouch
• grumbling
• murmur
• rumble
• scold

NearBy Words:

• grumbler