State Department vs United States

State Department and United States both are nouns.

Word	Noun	Adjective	Verb	Adverb
State Department	Yes	No	No	No
United States	Yes	No	No	No

State Department (noun)	United States (noun)
the federal department in the United States that sets and maintains foreign policies	the executive and legislative and judicial branches of the federal government of the United States
a department of government in one of the 50 states	North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776