Where does “cyrniawa” come from?

cyrniawa (Polish) comes from Polish czerń, from Polish Czarny, from Old Polish czarny, from Proto-Slavic *čь̀rnъ — black.

Ancestry of “cyrniawa”, step by step

StepLanguageWordMeaning
1Polishczerńblack
2PolishCzarnyblack
3Old Polishczarnyblack
4Proto-Slavic*čь̀rnъblack
Every word from Proto-Slavic *čь̀rnъ →Every word from Old Polish czarny →Every word from Polish Czarny →