Where does “یکدیگر” come from?

یکدیگر (Persian) comes from Persian دیگر, from Proto-Iranian dwitī́yakarah, from Proto-Iranian dwitī́yah, from Proto-Indo-Iranian dwitī́yas, from Proto-Indo-European dwitíyos, from Proto-Indo-European dwi-, from Proto-Indo-European dwóh₁ — two.

یکدیگر (Persian): each other, one another

Definitions

  1. each other, one another

Ancestry of “یکدیگر”, step by step

یکدیگر traces back through two separate lines of ancestry.

via Persian دیگر

StepLanguageWordMeaning
1Persianدیگرother; another; no more
2Proto-Iraniandwitī́yakarahsecond, another; another time
3Proto-Iraniandwitī́yahsecond
4Proto-Indo-Iraniandwitī́yassecond
5Proto-Indo-Europeandwitíyos—
6Proto-Indo-Europeandwi-two; apart, asunder
7Proto-Indo-Europeandwóh₁two

via Persian یک

StepLanguageWordMeaning
1PersianیکAPI •; one
2Middle Persianʾywk'—
3Middle Persianʾy—
4Proto-IranianHáywahone
5Proto-Indo-IranianHáywasjust, only; one
6Proto-Indo-Europeanóynosone; single
Every word from Proto-Indo-European dwóh₁ →Every word from Proto-Indo-European dwi- →Every word from Proto-Indo-European dwitíyos →