Where does “-ος” come from?

-ος (Ancient Greek) comes from Proto-Hellenic *-os, from Proto-Indo-European -ós — Creates agent nouns from verb stems, denoting...

Ancestry of “-ος”, step by step

Step	Language	Word	Meaning
1	Proto-Hellenic	*-os	—
2	Proto-Indo-European	-ós	Creates agent nouns from verb stems, denoting...

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