lunation

From Medieval Latin lūnātiō.

• IPA^(key): /luːˈneɪʃən/

• Audio (Southern England):

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• Rhymes: -eɪʃən
• Hyphenation: lu‧na‧tion

lunation (plural lunations)

1. A month of an average of approximately 29.53 days, measured from a lunar phase until the return of that same phase.
   • 1357, John Mandeville, The Travels of Sir John Mandeville‎^[1], modernized spelling edition:

     And there is not the moon seen in all the lunation, save only the second quarter.

   • 1982 December 25, J. Grainger, “Gay-by-Gay Calendars at a Glance”, in Gay Community News, volume 10, number 23, page 9:

     The seventh annual Lunar Calendar challenges the traditional structure of the calendar from a feminist perspective. The Lunar Calendar bases its months bases its months on lunations or 28 day lunar cycles, giving us thirteen in a calendar year.

2. The irregular period from one new moon until the next.

• synodic month
• lunar month

• Lutonian, Ultonian