NSWC vs bureau

NSWC and bureau both are nouns.

Word	Noun	Adjective	Verb	Adverb
NSWC	Yes	No	No	No
bureau	Yes	No	No	No

As nouns, bureau is a hypernym of NSWC; that is, bureau is a word with a broader meaning than NSWC:

NSWC: the agency that provides scientific and engineering and technical support for all aspects of surface warfare
bureau: an administrative unit of government

Other hypernyms of NSWC include agency, authority, federal agency, government agency, office.

NSWC (noun)	bureau (noun)
the agency that provides scientific and engineering and technical support for all aspects of surface warfare	furniture with drawers for keeping clothes
	an administrative unit of government