Where does “cimmerius” come from?

cimmerius (Latin) comes from Ancient Greek Κιμμέριος, from Proto-Iranian gamīra-.

Ancestry of “cimmerius”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Κιμμέριος	a Cimmerian
2	Proto-Iranian	gamīra-	—

cimmerius — Etymology, Origin & Word History | Etymology Explorer