What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
A former Japanese monetary unit with a standard weight of 4.76 momme (approx. 18 grams), based on a unit of weight of precious metals (varying between 4 and 5 momme).
Mid 19th century. From Japanese ryō (earlier ryau, riyau) former unit of weight and monetary unit from Middle Chinese.