Where does “pětka” come from?

pětka (Lower Sorbian) comes from Lower Sorbian pěta, from Proto-Slavic pęta, from Proto-Slavic pęti, from Proto-Balto-Slavic pínˀtei, from Proto-Indo-European (s)penh₁- — to twist; to weave.

pětka (Lower Sorbian): Diminutive of pěta; inflection of pětk: ##...

Definitions

Diminutive of pěta; inflection of pětk: ##...

Ancestry of “pětka”, step by step

Step	Language	Word	Meaning
1	Lower Sorbian	pěta	heel
2	Proto-Slavic	pęta	heel
3	Proto-Slavic	pęti	to stretch; to tie, fix together
4	Proto-Balto-Slavic	pínˀtei	to braid; to stretch
5	Proto-Indo-European	(s)penh₁-	to twist; to weave

Every word from Proto-Indo-European (s)penh₁- →Every word from Proto-Balto-Slavic pínˀtei →Every word from Proto-Slavic pęti →