Where does “jękać” come from?

jękać (Polish) comes from Proto-Slavic ękati, from Proto-Balto-Slavic ink-.

Ancestry of “jękać”, step by step

StepLanguageWordMeaning
1Proto-Slavicękatito moan
2Proto-Balto-Slavicink-
Every word from Proto-Balto-Slavic ink-Every word from Proto-Slavic ękati