Dictionary.com
Thesaurus.com

insularize

American  
[in-suh-luh-rahyz, ins-yuh-] / ˈɪn sə ləˌraɪz, ˈɪns yə- /
especially British, insularise

verb (used with object)

insularized, insularizing
  1. to make into an island or represent as insular.


Etymology

Origin of insularize

First recorded in 1890–95; insular + -ize