Where does “стопа́” come from?

стопа́ (Russian) comes from Proto-Slavic stǫpa, from Proto-Indo-European stebʰ‑.

Ancestry of “стопа́”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	stǫpa	mortar, a vessel where ingredients are ground;...
2	Proto-Indo-European	stebʰ‑	—

стопа́ — Etymology, Origin & Word History | Etymology Explorer