Where does “cieva” come from?

cieva (Old Czech) comes from Proto-Slavic cěva, from Proto-Balto-Slavic koy-w-aʔ, from Proto-Indo-European koy-w-.

Ancestry of “cieva”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	cěva	shin-bone, tube, bobbin, spool
2	Proto-Balto-Slavic	koy-w-aʔ	—
3	Proto-Indo-European	koy-w-	—

cieva — Etymology, Origin & Word History | Etymology Explorer