murmur

nouns

a low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech
murmur, murmuration, murmuring, mussitation, mutter, muttering
is derived from
murmurous
is derived from
murmurer
a schwa that is incidental to the pronunciation of a consonant
murmur, murmur vowel
an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves
cardiac murmur, heart murmur, murmur
a complaint uttered in a low and indistinct tone
grumble, grumbling, murmur, murmuring, mutter, muttering

verbs

speak softly or indistinctly
"She murmured softly to the baby in her arms"
murmur
is derived from
murmuration
is derived from
murmuring
is derived from
murmurer
is a type of (narrower)
express in speech
"She talks a lot of nonsense"; "This depressed patient does not verbalize"
mouth, speak, talk, utter, verbalise, verbalize
make complaining remarks or noises under one's breath
"she grumbles when she feels overworked"
croak, gnarl, grumble, murmur, mutter
is derived from
murmuring
is derived from
murmurer