Karat
来自Big Physics
late Middle English: from French, from Italian carato, from Arabic qīrāṭ (a unit of weight), from Greek keration ‘fruit of the carob’ (also denoting a unit of weight), diminutive of keras ‘horn’, with reference to the elongated seed pod of the carob.
wiktionary
From Middle English carat, from Middle French carat, from Medieval Latin carratus. Doublet of ceratium.
etymonline
karat (n.)
1854, spelling variant of carat (q.v.). In U.S., karat is used for "proportion of fine gold in an alloy" and carat for "measure of weight of a precious stone."
