West Coast of the United States vs geographic area

West Coast of the United States and geographic area both are nouns.

Word	Noun	Adjective	Verb	Adverb
West Coast of the United States	Yes	No	No	No
geographic area	Yes	No	No	No

West Coast of the United States (noun)	geographic area (noun)
the western seaboard of the United States from Washington to southern California	a demarcated area of the Earth