Where does “кошевина” come from?

кошевина (Serbo-Croatian) comes from Serbo-Croatian ко̀са, from Serbo-Croatian ко̑с, from Proto-Slavic kǫsъ, from Proto-Slavic kǫsati, from Proto-Slavic kǫ̑sъ — piece.

Definitions

Ancestry of “кошевина”, step by step

StepLanguageWordMeaning
1Serbo-Croatianко̀саhair of a person, on the head
2Serbo-Croatianко̑сslanted
3Proto-Slavickǫsъpiece
4Proto-Slavickǫsatito bite
5Proto-Slavickǫ̑sъpiece
Every word from Proto-Slavic kǫ̑sъ →Every word from Proto-Slavic kǫsati →Every word from Proto-Slavic kǫsъ →