An Etymological Dictionary of the German Language/Annotated/As

by Friedrich Kluge

As, neuter, Aß, Modern High German only, from the equivalent French as, masculine, ‘the ace (of dice or cards), a small weight’ (Latin as). In Middle High German the prevalent term for the ‘ace (of dice)’ was esse, which comes from Latin assis (a later collateral form of as). Compare Daus.