/ Dictionary / Index G Guam: Meaning and Definition of Find definitions for: Guam Pronunciation: (gwäm), [key] — n. an island, belonging to the U.S., in the N Pacific, E of the Philippines: the largest of the Marianas group; U.S. naval station. 84,996; 206 sq. mi. (535 sq. km). Cap.: Agaña. Abbr.: GU (for use with zip code). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: guam (Thesaurus) guajira guan Related Content Daily Word Quiz: stringent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language