CDC vs government agency

CDC and government agency both are nouns.

Word	Noun	Adjective	Verb	Adverb
CDC	Yes	No	No	No
government agency	Yes	No	No	No

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

CDC: a federal agency in the Department of Health and Human Services; located in Atlanta; investigates and diagnoses and tries to control or prevent diseases (especially new and unusual diseases)
government agency: an administrative unit of government

Other hypernyms of CDC include agency, authority, bureau, federal agency, office.

CDC (noun)	government agency (noun)
a federal agency in the Department of Health and Human Services; located in Atlanta; investigates and diagnoses and tries to control or prevent diseases (especially new and unusual diseases)	an administrative unit of government