CIA vs independent agency

CIA and independent agency both are nouns.

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

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

CIA: an independent agency of the United States government responsible for collecting and coordinating intelligence and counterintelligence activities abroad in the national interest; headed by the Director of Central Intelligence under the supervision of the President and National Security Council
independent agency: an agency of the United States government that is created by an act of Congress and is independent of the executive departments

Other hypernyms of CIA include United States intelligence agency.

CIA (noun)	independent agency (noun)
an independent agency of the United States government responsible for collecting and coordinating intelligence and counterintelligence activities abroad in the national interest; headed by the Director of Central Intelligence under the supervision of the President and National Security Council	an agency of the United States government that is created by an act of Congress and is independent of the executive departments