Where does “Séléné” come from?

Séléné (French) comes from Ancient Greek σελήνη, from Ancient Greek Σέλας.

Ancestry of “Séléné”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	σελήνη	moon; month; a moon-shaped cake
2	Ancient Greek	Σέλας	—

Séléné — Etymology, Origin & Word History | Etymology Explorer