Where does “срѣдьнъ” come from?

срѣдьнъ (Old Church Slavonic) comes from Proto-Slavic serdьnъ, from Proto-Slavic serda, from Proto-Balto-Slavic śerd-, from Proto-Indo-European ḱerd- — heart.

Ancestry of “срѣдьнъ”, step by step

StepLanguageWordMeaning
1Proto-Slavicserdьnъmiddle, central
2Proto-Slavicserdamiddle; Wednesday
3Proto-Balto-Slavicśerd-—
4Proto-Indo-Europeanḱerd-heart

Words derived from “срѣдьнъ”

Every word from Proto-Indo-European ḱerd- →Every word from Proto-Balto-Slavic śerd- →Every word from Proto-Slavic serda →