U. S. Air Force vs bureau

U. S. Air Force and bureau both are nouns.

Word	Noun	Adjective	Verb	Adverb
U. S. Air Force	Yes	No	No	No
bureau	Yes	No	No	No

As nouns, bureau is a hypernym of U. S. Air Force; that is, bureau is a word with a broader meaning than U. S. Air Force:

U. S. Air Force: the airforce of the United States of America; the agency that defends the United States through control and exploitation of air and space
bureau: an administrative unit of government

Other hypernyms of U. S. Air Force include agency, authority, federal agency, government agency, office.

U. S. Air Force (noun)	bureau (noun)
the airforce of the United States of America; the agency that defends the United States through control and exploitation of air and space	furniture with drawers for keeping clothes
	an administrative unit of government