Internal Revenue Service vs Treasury

Internal Revenue Service and Treasury both are nouns.

Word	Noun	Adjective	Verb	Adverb
Internal Revenue Service	Yes	No	No	No
Treasury	Yes	No	No	No

Internal Revenue Service (noun)	Treasury (noun)
the bureau of the Treasury Department responsible for tax collections	the federal department that collects revenue and administers federal finances; the Treasury Department was created in 1789
	the British cabinet minister responsible for economic strategy
	negotiable debt obligations of the United States government which guarantees that interest and principal payments will be paid on time