Where does “neother-” come from?

neother- (Middle English) comes from Old English niþer-, from Old English niþer, from Proto-Germanic niþer, from Proto-Indo-European niter.

Ancestry of “neother-”, step by step

StepLanguageWordMeaning
1Old Englishniþer-below, beneath; situated in a lower position,...
2Old Englishniþerdown; downstairs
3Proto-Germanicniþerdown, downwards
4Proto-Indo-Europeanniter—
Every word from Proto-Indo-European niter →Every word from Proto-Germanic niþer →Every word from Old English niþer →