1350–1400; Medieval Latin murmuratio (“murmuring, grumbling”). The “flock of starlings” sense is probably derived from the sound of the very large groups that starlings form at dusk.

• (General American) IPA^(key): /ˌmɝməˈɹeɪʃən/
• (Received Pronunciation) IPA^(key): /ˌmɜːməˈɹeɪʃən/
• Rhymes: -eɪʃən

murmuration (countable and uncountable, plural murmurations)

1. An act or instance of murmuring.
2. (ornithology, collective) A flock of starlings.
   • 1893 September 27, The Bazaar, the Exchange and Mart, London, page 800, column 3:

     "Oh! I wasted most of my morning crawling to a murmuration of starlings, which I foolishly mistook for congregation of plover."

   • 2013 March 19, Ed Yong, “How the Science of Swarms Can Help Us Fight Cancer and Predict the Future”, in Wired‎^[1]:

     The same dynamics can be seen in starlings: On clear winter evenings, murmurations of the tiny blackish birds gather in Rome’s sunset skies, wheeling about like rustling cloth.

   • 2017 July 29, “Solved, the riddle of starlings' aerial ballet: Birds use acrobatics to ward off creatures of prey”, in Daily Mail‎^[2]:

     Professor Anne Goodenough, an applied ecologist at the University of Gloucestershire who led the research, said: ‘It appears murmuration has become the norm – a general way for the starlings to stay safe from predators.’

3. An emergent order in a multi-agent social system.

• Flocking (behavior) on Wikipedia.Wikipedia
• Example of starling murmuration from YouTube.