Central America vs accumulation

Central America and accumulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
Central America	Yes	No	No	No
accumulation	Yes	No	No	No

As nouns, accumulation is a hypernym of Central America; that is, accumulation is a word with a broader meaning than Central America:

Other hypernyms of Central America include aggregation, assemblage, collection.

Central America (noun)	accumulation (noun)
the nations of Central America collectively	the act of accumulating
the isthmus joining North America and South America; extends from the southern border of Mexico to the northern border of Colombia	several things grouped together or considered as a whole
	(finance) profits that are not paid out as dividends but are added to the capital base of the corporation
	an increase by natural growth or addition