British Dictionary definitions for isle of guernsey
an island in the English Channel: the second largest of the Channel Islands, which, with Alderney and Sark, Herm, Jethou, and some islets, forms the bailiwick of Guernsey; finance, market gardening, dairy farming, and tourism. Capital: St Peter Port. Pop: 65 605 (2013). Area: 63 sq km (24.5 sq miles)
a breed of dairy cattle producing rich creamy milk, originating from the island of Guernsey
(sometimes not capital) a seaman's knitted woollen sweater
(not capital) (Austral) a sleeveless woollen shirt or jumper worn by a football player
(Austral) get a guernsey, to be selected or gain recognition for something
breed of cattle, 1834, from the Channel Island where it was bred; the island name is Viking. Like neighboring Jersey, it was also taken as the name for a coarse, close-fitting vest of wool (1839), and in Australia the word supplies many of the usages of jersey in U.S.