Where does “καθείς” come from?

καθείς (Ancient Greek) comes from Ancient Greek κατά, from Ancient Greek καταστερίζω, from Ancient Greek ἀστήρ, from Proto-Hellenic astḗr, from Proto-Indo-European h₂stḗr, from Proto-Indo-European h₂eHs- — to be/become dry; to burn, to glow; hearth.

Ancestry of “καθείς”, step by step

καθείς traces back through two separate lines of ancestry.

via Ancient Greek κατά

StepLanguageWordMeaning
1Ancient Greekκατά
2Ancient Greekκαταστερίζωto place among the stars; I put among the stars
3Ancient Greekἀστήρa celestial body; illustrious person; starfish
4Proto-Hellenicastḗrstar
5Proto-Indo-Europeanh₂stḗrstar
6Proto-Indo-Europeanh₂eHs-to be/become dry; to burn, to glow; hearth

via Ancient Greek εἷς

StepLanguageWordMeaning
1Ancient Greekεἷςone
2Proto-Hellenichenscardinal number 1 Previous: n/a Next: *dúwō;...
3Proto-Indo-Europeansḗmone
4Proto-Indo-Europeansem-together, one
Every word from Proto-Indo-European h₂eHs-Every word from Proto-Indo-European h₂stḗrEvery word from Proto-Hellenic astḗr