[n] a schwa that is incidental to the pronunciation of a consonant
[n] a complaint uttered in a low and indistinct tone
[n] a low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech
[n] an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves
[v] complain quietly
[v] speak softly or indistinctly; "She murmured softly to the baby in her arms"
cardiac murmur, croak, gnarl, grumble, grumble, grumbling, heart murmur, murmur vowel, murmuration, murmuring, murmuring, mussitation, mutter, mutter, mutter, muttering, muttering