lunation

From Medieval Latin lūnātiō.

• IPA^(key): /luːˈneɪʃən/
• 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, modernized spelling edition:

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

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

• synodic month
• lunar month

• Lutonian, Ultonian