Where does “subfeu” come from?

subfeu (English) comes from English sub-, from Latin sub-, from Proto-Indo-European upó, from Proto-Indo-European h₃ewp-.

subfeu (English): A feu sublet by a vassal to a subvassal: a right...

Definitions

Step	Language	Word	Meaning
1	English	sub-	under, beneath; subsidiary, secondary; almost,...
2	Latin	sub-	under, sub
3	Proto-Indo-European	upó	under, below
4	Proto-Indo-European	h₃ewp-	—