Where does “ϑōp-” come from?

ϑōp- (Proto-Albanian) comes from Proto-Indo-European ḱeh3-(i-) — to sharpen, whet.

Ancestry of “ϑōp-”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	ḱeh3-(i-)	to sharpen, whet

ϑōp- — Etymology, Origin & Word History | Etymology Explorer