Where does “wkładnik” come from?

wkładnik (Polish) comes from Polish wkładać, from Old Polish wkładać, from Old Polish kładać, from Proto-Slavic *kladati.

Ancestry of “wkładnik”, step by step

StepLanguageWordMeaning
1Polishwkładaćto put in, to insert
2Old Polishwkładaćto put on
3Old Polishkładać—
4Proto-Slavic*kladati—
Every word from Proto-Slavic *kladati →Every word from Old Polish kładać →Every word from Old Polish wkładać →