Where does “nether” come from?

nether (Middle English) comes from Old English niþera, from Proto-Germanic niþeraz, from Proto-Indo-European h₁én — in.

Ancestry of “nether”, step by step

StepLanguageWordMeaning
1Old Englishniþeralower, lowest, under; inferior
2Proto-Germanicniþeraz—
3Proto-Indo-Europeanh₁énin

Words derived from “nether”

Every word from Proto-Indo-European h₁én →Every word from Proto-Germanic niþeraz →Every word from Old English niþera →