Central America vs Central American nation

Central America and Central American nation both are nouns.

Word	Noun	Adjective	Verb	Adverb
Central America	Yes	No	No	No
Central American nation	Yes	No	No	No

Central America (noun)	Central American nation (noun)
the nations of Central America collectively	any one of the countries occupying Central America; these countries (except for Belize and Costa Rica) are characterized by low per capita income and unstable governments
the isthmus joining North America and South America; extends from the southern border of Mexico to the northern border of Colombia