'Murmuration' definitions:

Definition of 'murmuration'

From: WordNet
noun
A low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech [syn: mutter, muttering, murmur, murmuring, murmuration, mussitation]

Definition of 'Murmuration'

From: GCIDE
  • Murmuration \Mur`mur*a"tion\, n. [L. murmuratio.] The act of murmuring; a murmur. [Obs.] --Skelton. [1913 Webster]