An Etymological Dictionary of the German Language/Annotated/Niet
Niet, neuter, from the equivalent Middle High German niet, masculine and feminine, ‘bolt’; Old High German *hniot is not recorded with this sense. The word is connected with Old High German hniotan, ‘to fasten,’ Old Icelandic hnjóða, verb, ‘to strike, hammer, fix firmly’; the Teutonic root hnud, pre-Teutonic knut, has not yet been found in other languages.