Where does “равьнъ” come from?

равьнъ (Church Slavonic) comes from Proto-Slavic orvьnъ, from Proto-Slavic -ьnъ — -ish, -ic, -al, -ed; From adjectives.

Ancestry of “равьнъ”, step by step

StepLanguageWordMeaning
1Proto-Slavicorvьnъstraight; even
2Proto-Slavic-ьnъ-ish, -ic, -al, -ed; From adjectives
Every word from Proto-Slavic -ьnъ →Every word from Proto-Slavic orvьnъ →