Where does “-ινος” come from?

-ινος (Ancient Greek) comes from Proto-Indo-European -iHnos, from Proto-Indo-European -no- — adjectival suffix.

Ancestry of “-ινος”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	-iHnos	Creates adjectives of materials
2	Proto-Indo-European	-no-	adjectival suffix

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