U.S. government vs legislative branch

U.S. government and legislative branch both are nouns.

Word	Noun	Adjective	Verb	Adverb
U.S. government	Yes	No	No	No
legislative branch	Yes	No	No	No

U.S. government (noun)	legislative branch (noun)
the executive and legislative and judicial branches of the federal government of the United States	the branch of the United States government that has the power of legislating