State Department vs Foreign Service

State Department and Foreign Service both are nouns.

Word	Noun	Adjective	Verb	Adverb
State Department	Yes	No	No	No
Foreign Service	Yes	No	No	No

State Department (noun)	Foreign Service (noun)
the federal department in the United States that sets and maintains foreign policies	the part of the State Department that supplies diplomats for the United States embassies and consulates around the world
a department of government in one of the 50 states