Where does “gein” come from?

gein (German) comes from Ancient Greek γήινος, from Ancient Greek -ῐνος, from Proto-Indo-European -iHnos, from Proto-Indo-European -no- — adjectival suffix.

Ancestry of “gein”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	γήινος	of or pertaining to earth
2	Ancient Greek	-ῐνος	added to nouns or adverbs to form adjectives relating to material, time, and so on: made of, during the time of
3	Proto-Indo-European	-iHnos	Creates adjectives of materials
4	Proto-Indo-European	-no-	adjectival suffix

Words derived from “gein”

gein

Every word from Proto-Indo-European -no- →Every word from Ancient Greek -ῐνος →Every word from Proto-Indo-European -iHnos →