/ Thesaurus / N Synonyms of north island Find synonyms for: Noun1. North Islandusage: the smaller but more populous of two main islands of New Zealand; separated from South Island by Cook StraitWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language