Where does “??” come from?

?? (Sauraseni Prakrit) comes from Sanskrit दर, from Proto-Indo-Aryan d(ʰ)wā́r, from Proto-Indo-Iranian dʰwā́r, from Proto-Indo-European dʰwṓr, from Proto-Indo-European dʰwer- — door.

Ancestry of “??”, step by step

StepLanguageWordMeaning
1Sanskritदरfear; cleaving, split
2Proto-Indo-Aryand(ʰ)wā́r—
3Proto-Indo-Iraniandʰwā́r—
4Proto-Indo-Europeandʰwṓrdoor
5Proto-Indo-Europeandʰwer-door

Words derived from “??”

Every word from Proto-Indo-European dʰwer- →Every word from Proto-Indo-European dʰwṓr →Every word from Proto-Indo-Iranian dʰwā́r →