Where does “ei” come from?

ei (Middle Low German) comes from Old Saxon ei, 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
1Old Saxoneiegg
2Proto-West Germanicaijegg
3EnglishiceWater in frozen form; Any frozen volatile...
4Middle Englishisice; That which is short-lived like ice; icy...
5Old Englishīsice
6Proto-West Germanicīsice
7Proto-Germanicīsąice
8Proto-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 →