Where does “Месопотамия” come from?

Месопотамия (Bulgarian) comes from Old Church Slavonic месопотамиꙗ, from Ancient Greek Μεσοποταμία, from Ancient Greek μεσοποτάμιος, from Ancient Greek μέσος, from Ancient Greek σφαῖρα, from Ancient Greek -ειδής, from Ancient Greek -ής, from Proto-Indo-European -ēs — Creates action nouns or result nouns from verbs;...

Ancestry of “Месопотамия”, step by step

Step	Language	Word	Meaning
1	Old Church Slavonic	месопотамиꙗ	—
2	Ancient Greek	Μεσοποταμία	land between the rivers
3	Ancient Greek	μεσοποτάμιος	between rivers
4	Ancient Greek	μέσος	middle of, between, amidst; half; of middle...
5	Ancient Greek	σφαῖρα	ball, globe, sphere
6	Ancient Greek	-ειδής	like, connected to, from the nature of, full of;...
7	Ancient Greek	-ής	adjective suffix
8	Proto-Indo-European	-ēs	Primarily forms adjectival bahuvrīhi compounds
9	Proto-Indo-European	-ess	—
10	Proto-Indo-European	-os	Creates action nouns or result nouns from verbs;...

Every word from Proto-Indo-European -os →Every word from Ancient Greek -ειδής →Every word from Ancient Greek σφαῖρα →