Where does “ei” come from?

ei (Old Dutch) comes from Proto-West Germanic aij, from English ice, from Middle English is, from Old English īs, from Proto-West Germanic īs, from Proto-Germanic īsą, from Proto-Indo-European h₁eyH- — ice, frost.

Ancestry of “ei”, step by step

StepLanguageWordMeaning
1Proto-West Germanicaijegg
2EnglishiceWater in frozen form; Any frozen volatile...
3Middle Englishisice; That which is short-lived like ice; icy...
4Old Englishīsice
5Proto-West Germanicīsice
6Proto-Germanicīsąice
7Proto-Indo-Europeanh₁eyH-ice, frost

Words derived from “ei”

Every word from Proto-Indo-European h₁eyH- →Every word from Proto-Germanic īsą →Every word from Proto-West Germanic īs →