North America vs assemblage

North America and assemblage both are nouns.

Word	Noun	Adjective	Verb	Adverb
North America	Yes	No	No	No
assemblage	Yes	No	No	No

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

Other hypernyms of North America include accumulation, aggregation, collection.

North America (noun)	assemblage (noun)
the nations of the North American continent collectively	the social act of assembling
a continent (the third largest) in the western hemisphere connected to South America by the Isthmus of Panama	a system of components assembled together for a particular purpose
	a group of persons together in one place
	several things grouped together or considered as a whole