Where does “*sek” come from?

*sek (Proto-Germanic) comes from Proto-Indo-European swe-, from Proto-Indo-European swé — self.

Ancestry of “*sek”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	swe-	self
2	Proto-Indo-European	swé	self

*sek — Etymology, Origin & Word History | Etymology Explorer