Where does “Iaxartes” come from?

Iaxartes (English) comes from Latin Iaxartes, from Ancient Greek Ἰαξάρτης.

Ancestry of “Iaxartes”, step by step

Step	Language	Word	Meaning
1	Latin	Iaxartes	Syr Darya river
2	Ancient Greek	Ἰαξάρτης	—

Iaxartes — Etymology, Origin & Word History | Etymology Explorer