Where does “чёрствость” come from?

чёрствость (Russian) comes from Russian чёрствый, from Old East Slavic чьрствъ, from Proto-Slavic čьrstvъ, from Proto-Balto-Slavic kirst(w)os, from Proto-Indo-European krt-two-.

чёрствость (Russian): callousness, hard-heartedness

Definitions

  1. callousness, hard-heartedness

Ancestry of “чёрствость”, step by step

StepLanguageWordMeaning
1Russianчёрствыйstale; hardhearted, callous
2Old East Slavicчьрствъ—
3Proto-Slavicčьrstvъfirm
4Proto-Balto-Slavickirst(w)os—
5Proto-Indo-Europeankrt-two-—
Every word from Proto-Indo-European krt-two- →Every word from Proto-Balto-Slavic kirst(w)os →Every word from Proto-Slavic čьrstvъ →