Where does “moonwatcher” come from?

moonwatcher (English) comes from English Moon, from Middle English Mone, from Old English mān, from Sanskrit महादेव, from Sanskrit महा, from Proto-Indo-Aryan maźʰā́, from Proto-Indo-Iranian maȷ́ʰā́, from Proto-Indo-European méǵh₂s — big, great.

Ancestry of “moonwatcher”, step by step

moonwatcher traces back through two separate lines of ancestry.

via English Moon

StepLanguageWordMeaning
1EnglishMoonThe Earth's moon; the sole natural satellite of the Earth, represented in astronomy and astrology by ☾
2Middle EnglishMoneA lamentation; a sorrowful moan or expression
3Old Englishmānbad, criminal, false; shameful act; crime;...
4Sanskritमहादेवthe "great God"
5Sanskritमहाcombining form of महत्; buffalo; great, large,...
6Proto-Indo-Aryanmaźʰā́
7Proto-Indo-Iranianmaȷ́ʰā́big, great
8Proto-Indo-Europeanméǵh₂sbig, great

via English watcher

StepLanguageWordMeaning
1EnglishwatcherSomeone who watches or observes; Someone who...
2Middle Englishwacchere
Every word from Proto-Indo-European méǵh₂s