Where does “under” come from?

under (Old Frisian) comes from Old Saxon undar, from Proto-Germanic under, from Proto-Indo-European h₁entér, from Proto-Indo-European h₁en — in; in, inside.

Ancestry of “under”, step by step

StepLanguageWordMeaning
1Old Saxonundarunder
2Proto-Germanicunderamong, between; under, beneath; under
3Proto-Indo-Europeanh₁entérbetween
4Proto-Indo-Europeanh₁enin; in, inside

Words derived from “under”

Every word from Proto-Indo-European h₁en →Every word from Proto-Indo-European h₁entér →Every word from Proto-Germanic under →