Where does “Полонне” come from?

Полонне (Ukrainian) comes from Ukrainian полони́на, from Proto-Slavic polnina, from Proto-Slavic polnъ, from Proto-Balto-Slavic palˀnas, from Proto-Indo-European polh₂-no-s, from Proto-Indo-European ploh₂-no-s, from Proto-Indo-European pleh₂- — flat.

Ancestry of “Полонне”, step by step

StepLanguageWordMeaning
1Ukrainianполони́наmountain pasture, mountain meadow, mountain clearing
2Proto-Slavicpolninabarren highlands, plateau; mountain
3Proto-Slavicpolnъwithout growth on it, barren, fruitless; flat,...
4Proto-Balto-Slavicpalˀnas
5Proto-Indo-Europeanpolh₂-no-s
6Proto-Indo-Europeanploh₂-no-s
7Proto-Indo-Europeanpleh₂-flat
Every word from Proto-Indo-European pleh₂-Every word from Proto-Indo-European ploh₂-no-sEvery word from Proto-Indo-European polh₂-no-s