Where does “Яўгенія” come from?

Яўгенія (Belarusian) comes from Ancient Greek Εὐγενία, from Ancient Greek Εὐγένῐος.

Ancestry of “Яўгенія”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Εὐγενία	—
2	Ancient Greek	Εὐγένῐος	—

Яўгенія — Etymology, Origin & Word History | Etymology Explorer