English
interlunation
From inter- + lunation.
Proto-Indo-European *h₁én ‘in’
Proto-Indo-European *h₁entér ‘between’
Proto-Italic *n̥ter ‘between’
Latin inter ‘between’
English inter-
Proto-Indo-European *lewk- ‘bright’
…
Proto-Italic *louksnā ‘moon’
Latin lūna ‘moon’
Latin luno ‘bend in a crescent’
Medieval Latin lūnātiō ‘lunar month, lunation’
English lunation
Today it means
noun The interlunar period; the dark time between the old moon and new moon phases.
Language periods are conventional ranges, not dates for this word.
Etymograph / interlunation