independent agency vs office

independent agency and office both are nouns.

Word	Noun	Adjective	Verb	Adverb
independent agency	Yes	No	No	No
office	Yes	No	No	No

As nouns, office is a hypernym of independent agency; that is, office is a word with a broader meaning than independent agency:

independent agency: an agency of the United States government that is created by an act of Congress and is independent of the executive departments
office: an administrative unit of government

Other hypernyms of independent agency include agency, authority, bureau, federal agency, government agency.

independent agency (noun)	office (noun)
an agency of the United States government that is created by an act of Congress and is independent of the executive departments	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