[ad. (ultimately) Tamil kāsu (‘or perhaps some Konkani form of it’), name of a small coin, or weight of money:—Skr. karsha ‘a weight of silver or gold equal to 1/400 of a tulā’ (Williams); Singhalese kāsi coin. The early Portuguese writers represented the native word by cas, casse, caxa, the Fr. by cas, the Eng. by cass: the existing Pg. caixa and Eng. cash are due to a natural confusion with cash n.1 From an early date the Portuguese applied caixa (probably on the same analogy) to the small money of other foreign nations, such as that of the Malay Islands, and especially the Chinese, which was also naturally made into cash in English. (Yule.)]
A name applied by Europeans to various coins of low value in the East Indies and China: esp. a.a The basis of the monetary system which prevailed in Southern India up to 1818; in this system 80 cash = 1 fanam, 42 fanams = 1 star pagoda (about 7s. 8d.).