Where does “tartarus” come from?

tartarus (Medieval Latin) comes from Latin tartarus, from Ancient Greek Τάρταρος, from Ancient Greek Ταρτησσός, from Ancient Greek Ἡράκλειοι Στῆλαι.

tartarus (Medieval Latin): Tatar

Definitions

tartarus traces back through 3 separate lines of ancestry.

Step	Language	Word	Meaning
1	Latin	tartarus	A river of Venetia that used to flow into the Adriatic Sea, now called Tartaro
2	Ancient Greek	Τάρταρος	Tartarus
3	Ancient Greek	Ταρτησσός	Tartessus; Tartessos
4	Ancient Greek	Ἡράκλειοι Στῆλαι	—

Step	Language	Word	Meaning
1	Old Turkic	Tatar	—

Step	Language	Word	Meaning
1	Old Turkic	𐱃𐱃𐰺	A Tatar, a member of one of the major tribal confederations in the Mongolian Plateau (8th–12th centuries)