West Coast vs West Coast of the United States

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

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

As nouns, West Coast and West Coast of the United States are synonyms defined as:

West Coast and West Coast of the United States: the western seaboard of the United States from Washington to southern California

West Coast (noun)	West Coast of the United States (noun)
the western seaboard of the United States from Washington to southern California	the western seaboard of the United States from Washington to southern California