A Japanese unit of weight equal to 3.75 grams (approx. 0.132 oz).
This unit is now considered obsolete or archaic in Japan, except for special traditional purposes, such as weighing natural and cultured pearls.
Early 18th century; earliest use found in John Scheuchzer (1702–1729), physician and naturalist. From Japanese momme from mon former unit of length (about 2.64 cm) and currency (from Middle Chinese) + me eye.