government vs government department

government and government department both are nouns.

Word	Noun	Adjective	Verb	Adverb
government	Yes	No	No	No
government department	Yes	No	No	No

government (noun)	government department (noun)
the act of governing; exercising authority	a department of government
(government) the system or form by which a community or other political unit is governed
the study of government of states and other political units
the organization that is the governing authority of a political unit