Where does “inexorable” come from?

inexorable (Middle French) comes from Latin inexorabilis, from Latin exorabilis, from Latin exoro, from Latin ōrō, from Latin ōs, from Proto-Italic ōs, from Proto-Indo-European h₃ésth₁ — bone.

Ancestry of “inexorable”, step by step

StepLanguageWordMeaning
1Latininexorabilisrelentless, inexorable
2Latinexorabilisexorable; persuasive
3LatinexoroI persuade or win over; I beg, plead or entreat
4Latinōrōto orate, deliver a speech publicly
5Latinōsmouth
6Proto-Italicōsmouth
7Proto-Indo-Europeanh₃ésth₁bone

Words derived from “inexorable

Every word from Proto-Indo-European h₃ésth₁Every word from Proto-Italic ōsEvery word from Latin ōs