Where does “каѳисма” come from?

каѳисма (Old Church Slavonic) comes from Ancient Greek κάθισμα, from Ancient Greek καθίζω, from Ancient Greek κᾰτᾰ-, from Ancient Greek κατά, from Ancient Greek καταστερίζω, from Ancient Greek ἀστήρ, from Proto-Hellenic astḗr, from Proto-Indo-European h₂stḗr — to be/become dry; to burn, to glow; hearth.

Ancestry of “каѳисма”, step by step

StepLanguageWordMeaning
1Ancient Greekκάθισμαseat
2Ancient Greekκαθίζωto make to sit down, seat; to sit down, be...
3Ancient Greekκᾰτᾰ-fully; down; denoting motion downwards
4Ancient Greekκατά
5Ancient Greekκαταστερίζωto place among the stars; I put among the stars
6Ancient Greekἀστήρa celestial body; illustrious person; starfish
7Proto-Hellenicastḗrstar
8Proto-Indo-Europeanh₂stḗrstar
9Proto-Indo-Europeanh₂eHs-to be/become dry; to burn, to glow; hearth

Words derived from “каѳисма

Every word from Proto-Indo-European h₂eHs-Every word from Proto-Indo-European h₂stḗrEvery word from Proto-Hellenic astḗr