An Etymological Dictionary of the German Language/acht

by Friedrich Kluge

acht, num., ‘eight,’ from the equiv. MidHG. ahte, OHG. ahto, common to the Teut. and also to the Aryan groups. Comp. Goth. ahtau, AS. eahta, E. eight, Du. acht, OSax. ahto; further, Sans. ašṭáu, Gr. ὀκτώ, Lat. octo, OIr. ocht, Lith. asztu̇nì, prim. Aryan oktô, or rather oktôu, ‘eight.’ Respecting acht Tage see the historical note under Nacht.