Where does “Jęcz” come from?

Jęcz (Polish) comes from Polish jęczeć, from Proto-Slavic ęčati, from Proto-Balto-Slavic ink-.

Ancestry of “Jęcz”, step by step

StepLanguageWordMeaning
1Polishjęczećto moan; to whine, to complain
2Proto-Slavicęčatito wail, moan
3Proto-Balto-Slavicink-—
Every word from Proto-Balto-Slavic ink- →Every word from Proto-Slavic ęčati →Every word from Polish jęczeć →