largest of the Mariana Islands, in the W Pacific: an unincorporated territory of the U.S.: 209 sq mi (541 sq km); cap. Agana: abbrev. GU
An unincorporated territory of the United States, the largest and most southerly of the Mariana Islands in the western Pacific Ocean. Inhabited since ancient times by the Chamorro people, Guam was visited by Magellan in 1521 and ceded by Spain to the United States in 1898. Agana is the capital.
From the first letters of the member states.