Where does “Chatti” come from?

Chatti (Latin) comes from Ancient Greek Χάττοι, from Proto-Germanic *hattaz.

Ancestry of “Chatti”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Χάττοι	—
2	Proto-Germanic	*hattaz	—

Chatti — Etymology, Origin & Word History | Etymology Explorer