Where does “plecko” come from?

plecko (Polish) comes from Polish plecy, from Proto-Slavic pleťe, from Proto-Balto-Slavic plet-, from Proto-Indo-European pleth₂- — flat.

Ancestry of “plecko”, step by step

StepLanguageWordMeaning
1Polishplecyback
2Proto-Slavicpleťeshoulder
3Proto-Balto-Slavicplet-—
4Proto-Indo-Europeanpleth₂-flat
Every word from Proto-Indo-European pleth₂- →Every word from Proto-Balto-Slavic plet- →Every word from Proto-Slavic pleťe →