Where does “Mađar” come from?

Mađar (Serbo-Croatian) comes from Hungarian Magyar, from Old Hungarian mogyër, from Proto-Ugric mańćɜ.

Ancestry of “Mađar”, step by step

Step	Language	Word	Meaning
1	Hungarian	Magyar	—
2	Old Hungarian	mogyër	—
3	Proto-Ugric	mańćɜ	—

Mađar — Etymology, Origin & Word History | Etymology Explorer