ally vs nation

ally and nation both are nouns.

Word	Noun	Adjective	Verb	Adverb
ally	Yes	No	Yes	No
nation	Yes	No	No	No

As nouns, nation is a hypernym of ally; that is, nation is a word with a broader meaning than ally:

Other hypernyms of ally include body politic, commonwealth, country, land, res publica, state.

ally (noun)	nation (noun)
a friendly nation	a politically organized body of people under a single government
an associate who provides cooperation or assistance	the people who live in a nation or country
	a federation of tribes (especially Native American tribes)

ally (verb)	nation (verb)
become an ally or associate, as by a treaty or marriage