FHA vs federal agency

FHA and federal agency both are nouns.

Word	Noun	Adjective	Verb	Adverb
FHA	Yes	No	No	No
federal agency	Yes	No	No	No

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

FHA: the federal agency in the Department of Housing and Urban Development that insures residential mortgages
federal agency: an administrative unit of government

Other hypernyms of FHA include agency, authority, bureau, government agency, office.

FHA (noun)	federal agency (noun)
the federal agency in the Department of Housing and Urban Development that insures residential mortgages	an administrative unit of government