island → isular、insulate

island n. 岛
↓
isle [ailz] n. 岛
例：British Isles 不列颠群岛
↓
insular [ˈɪnsjələ(r)] a. 岛的；孤立的
insulate [ˈɪnsjʊleɪt] v. 隔离，使隔音，使绝缘