Where does “Венгри” come from?

Венгри (Chuvash) comes from Russian Ве́нгрия, from Russian венгр, from Polish Węgier, from Proto-Slavic ǫgъrinъ — Hungarian.

Ancestry of “Венгри”, step by step

Step	Language	Word	Meaning
1	Russian	Ве́нгрия	—
2	Russian	венгр	Hungarian
3	Polish	Węgier	Hungarian
4	Proto-Slavic	ǫgъrinъ	Hungarian

Венгри — Etymology, Origin & Word History | Etymology Explorer