Where does “Thurii” come from?

Thurii (Latin) comes from Ancient Greek Θούριοι — nominative plural of Θούρῐος.

Ancestry of “Thurii”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Θούριοι	nominative plural of Θούρῐος

Thurii — Etymology, Origin & Word History | Etymology Explorer