Where does “простъ” come from?

простъ (Old East Slavic) comes from Proto-Slavic prostъ, from Proto-Indo-European pro-sth₂o-.

Ancestry of “простъ”, step by step

StepLanguageWordMeaning
1Proto-Slavicprostъsimple, straight
2Proto-Indo-Europeanpro-sth₂o-—

Words derived from “простъ”

Every word from Proto-Indo-European pro-sth₂o- →Every word from Proto-Slavic prostъ →