Where does “Amu Darya” come from?

Amu Darya (English) comes from Persian دریا, from Middle Persian dlydʾp̄, from Old Persian 𐎭𐎼𐎹, from Proto-Iranian jráyah, from Proto-Indo-Iranian ȷ́ráyas — expanse, vastness; ocean.

Ancestry of “Amu Darya”, step by step

Amu Darya traces back through two separate lines of ancestry.

via Persian دریا

StepLanguageWordMeaning
1Persianدریاsea; ocean; river
2Middle Persiandlydʾp̄sea
3Old Persian𐎭𐎼𐎹sea
4Proto-Iranianjráyah—
5Proto-Indo-Iranianȷ́ráyasexpanse, vastness; ocean

via Persian آمودریا

StepLanguageWordMeaning
1Persianآمودریا—
Every word from Proto-Indo-Iranian ȷ́ráyas →Every word from Proto-Iranian jráyah →Every word from Old Persian 𐎭𐎼𐎹 →