| 1. | to utter words indistinctly or in a low tone, often as if talking to oneself; murmur. |
| 2. | to complain murmuringly; grumble. |
| 3. | to make a low, rumbling sound. |
| 4. | to utter indistinctly or in a low tone: to mutter complaints. |
| 5. | the act or utterance of a person who mutters. |