Where does “acht” come from?

acht (Translingual) comes from German Acht, from Middle High German āhte, from Old High German ahtô, from Proto-Germanic ahtō, from Proto-Germanic ahtōu, from Proto-Indo-European oḱtṓw, from Proto-Indo-European aḱ- — sharp, pointed; sharp, pointed, edgy; sharp,...

acht (Translingual): Spoken by a player during a match with one or more visually impaired players to indicate the eighth rank in algebraic notation