Where does “főnév” come from?

főnév (Hungarian) comes from Hungarian fő, from Hungarian fej, from Proto-Uralic päŋe — head.

főnév (Hungarian): substantive, noun

Definitions

Step	Language	Word	Meaning
1	Hungarian	fő	main, principal, key, chief, cardinal, core, most...
2	Hungarian	fej	head; head, mind, brain, intellect; heads,...
3	Proto-Uralic	päŋe	head

főnév — Etymology, Origin & Word History | Etymology Explorer