ghost town vs town

ghost town and town both are nouns.

Word	Noun	Adjective	Verb	Adverb
ghost town	Yes	No	No	No
town	Yes	No	No	No

As nouns, town is a hypernym of ghost town; that is, town is a word with a broader meaning than ghost town:

ghost town (noun)	town (noun)
a deserted settlement (especially in western United States)	the people living in a municipality smaller than a city
	an urban area with a fixed boundary that is smaller than a city
	an administrative division of a county