Channel Islands /ˈtʃænəl ˌaɪləndz/ noun2 •A group of islands of the Duchy of Normandy in the English Channel: Jersey, Guernsey, Alderney, Sark, Herm, Brecqhou, Lihou, Jethou and Burhou. •A group of islands off the coast of California, United States: San Miguel, Santa Rosa, Santa Cruz, Anacapa, San Nicolas, Santa Barbara, Santa Catalina, San Clemente.