Where does “polъdьnь” come from?

polъdьnь (Proto-Slavic) comes from Proto-Slavic dьnь, from Proto-Balto-Slavic dein-.

Ancestry of “polъdьnь”, step by step

polъdьnь traces back through two separate lines of ancestry.

via Proto-Slavic dьnь

StepLanguageWordMeaning
1Proto-Slavicdьnьday
2Proto-Balto-Slavicdein-

via Proto-Slavic polъ-

StepLanguageWordMeaning
1Proto-Slavicpolъ-half-

Words derived from “polъdьnь

Every word from Proto-Balto-Slavic dein-Every word from Proto-Slavic dьnь