Where does “Sveinn” come from?

Sveinn (Old Norse) comes from Old Norse sveinn, from Proto-Germanic swainaz, from Proto-Indo-European swé — self.

Ancestry of “Sveinn”, step by step

Step	Language	Word	Meaning
1	Old Norse	sveinn	boy, lad; servant, lackey
2	Proto-Germanic	swainaz	relative; kinsman; young man; herder; herdsman,...
3	Proto-Indo-European	swé	self

Sveinn — Etymology, Origin & Word History | Etymology Explorer