Where does “diapason” come from?

diapason (Latin) comes from Ancient Greek διαπασῶν, from Ancient Greek διά, from Proto-Indo-European dwís, from Proto-Indo-European dwóh₁ — two.

Ancestry of “diapason”, step by step

StepLanguageWordMeaning
1Ancient Greekδιαπασῶνoctave
2Ancient Greekδιάthroughout
3Proto-Indo-Europeandwístwice, doubly; in two
4Proto-Indo-Europeandwóh₁two

Words derived from “diapason

Every word from Proto-Indo-European dwóh₁Every word from Proto-Indo-European dwísEvery word from Ancient Greek διά