1.Definition: a complaint uttered in a low and indistinct tone

Related Noun(s):grumble, mutter

Category: General

2.Definition: a low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech

Related Noun(s):murmuration, mussitation, mutter

Category: General

3.Definition: a schwa that is incidental to the pronunciation of a consonant

Category: General

4.Definition: an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves

Category: General