carat

 
Pronunciation: /ˈkarət/

noun

  • 1a unit of weight for precious stones and pearls, equivalent to 200 milligrams: a half-carat diamond ring
  • 2 (US also karat) a measure of the purity of gold, pure gold being 24 carats: 23-carat gold

Origin:

late Middle English (in carat (sense 2)): 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