An Etymological Dictionary of the German Language/Annotated/acht

by Friedrich Kluge

acht, numeral, ‘eight,’ from the equivalent Middle High German ahte, Old High German ahto, common to the Teutonic and also to the Aryan groups. Compare Gothic ahtau, Anglo-Saxon eahta, English eight, Dutch acht, Old Saxon ahto; further, Sanscrit ašṭáu, Greek ὀκτώ, Latin octo, Old Irish ocht, Lithuanian asztu̇nì, primary Aryan oktô, or rather oktôu, ‘eight.’ Respecting acht Tage see the historical note under Nacht.