Where does “sěver” come from?

sěver (Old Czech) comes from Proto-Slavic sěverъ, from Proto-Balto-Slavic śḗˀweras, from Proto-Indo-European ḱeh₁wer-o-.

Ancestry of “sěver”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	sěverъ	north
2	Proto-Balto-Slavic	śḗˀweras	—
3	Proto-Indo-European	ḱeh₁wer-o-	—

sěver — Etymology, Origin & Word History | Etymology Explorer