United States Navy vs office

United States Navy and office both are nouns.

Word	Noun	Adjective	Verb	Adverb
United States Navy	Yes	No	No	No
office	Yes	No	No	No

As nouns, office is a hypernym of United States Navy; that is, office is a word with a broader meaning than United States Navy:

United States Navy: the navy of the United States of America; the agency that maintains and trains and equips combat-ready naval forces
office: an administrative unit of government

Other hypernyms of United States Navy include agency, authority, bureau, federal agency, government agency.

United States Navy (noun)	office (noun)
the navy of the United States of America; the agency that maintains and trains and equips combat-ready naval forces	a religious rite or service prescribed by ecclesiastical authorities
	the actions and activities assigned to or required or expected of a person or group
	a job in an organization
	place of business where professional or clerical duties are performed
	professional or clerical workers in an office
	an administrative unit of government
	(of a government or government official) holding an office means being in power