Patent Office vs federal agency

Patent Office and federal agency both are nouns.

Word	Noun	Adjective	Verb	Adverb
Patent Office	Yes	No	No	No
federal agency	Yes	No	No	No

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

Patent Office: the government bureau in the Department of Commerce that keeps a record of patents and trademarks and grants new ones
federal agency: an administrative unit of government

Other hypernyms of Patent Office include agency, authority, bureau, government agency, office.

Patent Office (noun)	federal agency (noun)
the government bureau in the Department of Commerce that keeps a record of patents and trademarks and grants new ones	an administrative unit of government