Where does “méro-” come from?

méro- (French) comes from Ancient Greek μέρος, from Proto-Hellenic *(h)méros.

Ancestry of “méro-”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	μέρος	part, component, region; share, portion; one's...
2	Proto-Hellenic	*(h)méros	—

méro- — Etymology, Origin & Word History | Etymology Explorer