Lunations

Part of speech: noun

Definitions

1. The phases of the moon during its monthly cycle, marked by specific changes in appearance from new moon to full moon and back again
2. The concept of lunar months characterized by the cyclical nature of moonlight as it waxes and wanes in a consistent pattern
3. A term describing the periodic appearances of the moon, encompassing its various stages seen over a 29.5-day interval

Etymology: Its root is the Latin "luna", meaning moon, which also lies behind English words from astronomy to folklore. The ending "-ation" turns a verb into a noun for a process, so the word names the moon completing one full cycle of phases. Medieval Latin likely had a similar form, "lunatio", which English adopted with the same sense. The most surprising relative is "lunatic". It descends from Latin "lunaticus", meaning "moon-struck", reflecting an old belief that the moon's changing phases could drive people to madness. Lunacy was once thought to rise and fall with the moon, so a term for the lunar cycle and a word for insanity share the same root.