Where does “eri” come from?

eri (Proto-Finnic) comes from Proto-Finnic erä, from Proto-Finno-Ugric erä — apart.

Ancestry of “eri”, step by step

eri traces back through two separate lines of ancestry.

via Proto-Finnic erä

StepLanguageWordMeaning
1Proto-Finniceräapart, separate
2Proto-Finno-Ugriceräapart

via Proto-Indo-Iranian er-

StepLanguageWordMeaning
1Proto-Indo-Iranianer-—
Every word from Proto-Finno-Ugric erä →Every word from Proto-Finnic erä →