An Etymological Dictionary of the German Language/nichts

by Friedrich Kluge

nichts, pronom. subst., ‘nothing,’ ModHG. only, in MidHG. niht. It originated from MidHG. nihtes niht, an emphatic form of the simple niht, which was ultimately omitted; the ModHG. dial. form nichtst is probably based directly on the MidHG. phrase, which in late MidHG. appears as nihtzit.