一いち指ゆび当あたり

noun

span (unit of length)

A traditional Japanese unit of length, roughly the distance from the tip of the thumb to the tip of the little finger when the hand is spread. Rare in modern usage; mainly encountered in historical or traditional contexts.

• 昔むかしの日本にほんでは、一いち指ゆび当あたりは約やく18センチメートルとされていた。

  In old Japan, one span was considered to be about 18 centimeters.