1.a low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech
2.a schwa that is incidental to the pronunciation of a consonant
3.an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves
4.a complaint uttered in a low and indistinct tone
1.speak softly or indistinctly;
She murmured softly to the baby in her arms
2.make complaining remarks or noises under one's breath;
she grumbles when she feels overworked