independent agency vs agency

independent agency and agency both are nouns.

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

As nouns, agency is a hypernym of independent agency; that is, agency 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
agency: an administrative unit of government

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

independent agency (noun)	agency (noun)
an agency of the United States government that is created by an act of Congress and is independent of the executive departments	to have the ability to produce a particular effect or achieve an end
	an administrative unit of government
	a business or organization that provides a particular service, especially the mediation of transactions between two parties
	the state of serving as an official and authorized delegate or agent
	the state of being in action or exerting power