United Mexican States vs Gulf of Campeche

United Mexican States and Gulf of Campeche both are nouns.

Word	Noun	Adjective	Verb	Adverb
United Mexican States	Yes	No	No	No
Gulf of Campeche	Yes	No	No	No

United Mexican States (noun)	Gulf of Campeche (noun)
a republic in southern North America; became independent from Spain in 1810	a part of the Gulf of Mexico to the west of Yucatan