Where does “undernethen” come from?

undernethen (Middle English) comes from Old English underneoþan, from Old English under, from Proto-Germanic under, from Proto-Indo-European h₁entér, from Proto-Indo-European h₁en — in; in, inside.

Ancestry of “undernethen”, step by step

StepLanguageWordMeaning
1Old Englishunderneoþanunderneath
2Old Englishunderunder, beneath
3Proto-Germanicunderamong, between; under, beneath; under
4Proto-Indo-Europeanh₁entérbetween
5Proto-Indo-Europeanh₁enin; in, inside
Every word from Proto-Indo-European h₁enEvery word from Proto-Indo-European h₁entérEvery word from Proto-Germanic under
undernethen — Etymology, Origin & Word History | Etymology Explorer