Where does “Ἀράξης” come from?

Ἀράξης (Ancient Greek) comes from Old Median Araxs(ā).

Ancestry of “Ἀράξης”, step by step

Step	Language	Word	Meaning
1	Old Median	Araxs(ā)	—

Ἀράξης — Etymology, Origin & Word History | Etymology Explorer