Defense Department vs Defense Information Systems Agency

Defense Department and Defense Information Systems Agency both are nouns.

Word	Noun	Adjective	Verb	Adverb
Defense Department	Yes	No	No	No
Defense Information Systems Agency	Yes	No	No	No

Defense Department (noun)	Defense Information Systems Agency (noun)
the federal department responsible for safeguarding national security of the United States; created in 1947	a combat support agency in the Department of Defense responsible for developing and operating and supporting information systems to serve the needs of the President and the Secretary of Defense and the Joint Chiefs of Staff