South America vs collection

South America and collection both are nouns.

Word	Noun	Adjective	Verb	Adverb
South America	Yes	No	No	No
collection	Yes	No	No	No

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

Other hypernyms of South America include accumulation, aggregation, assemblage.

South America (noun)	collection (noun)
the nations of the South American continent collectively	the act of gathering something together
a continent in the western hemisphere connected to North America by the Isthmus of Panama	a publication containing a variety of works
	request for a sum of money
	several things grouped together or considered as a whole