groat (n.)

medieval European coin, late 14c., probably from Middle Dutch groot, elliptical use of the adjective meaning "great, big" (in this case, "thick"), from the name of some large coin (for example the Bremen grote sware, and compare Medieval Latin grossi denarii in reference to a Prague coin) to distinguish it from smaller coins of the same name. Cognate with English great (adj.). Recognized from 13c. in various nations. The original English groat coined of 1351-2 was worth four pence; it was discontinued in 1622. Also see groschen.