Definition of lunation in US English:

lunation

noun

Astronomy
  • another term for lunar month
    • ‘However, the months no longer corresponded to lunations, as days were added to give a total year length of 365 days.’
    • ‘It is an alien model which exhibits a useful correlation between lunations, phases of horticultural activity and Gregorian calendar months - but it is based on a comparison that does not arise in people's minds.’
    • ‘Wondering if the same conditions of light and shadow would repeat during the next lunation, I tried, but failed, to see it.’
    • ‘Then, what they thought of it, had it any merit, were there others to which to make comparison, and why might the linkage between homicide rate and lunation be an attribute?’
    • ‘Given this - along with the use of the average length of the lunation and a number of other rules - a fully calculated calendar was possible.’

Origin

Late Middle English: from medieval Latin lunatio(n-), from Latin luna ‘moon’.

Pronunciation

lunation

/lo͞oˈnāSHən//luˈneɪʃən/