East Coast of the United States vs geographic region

East Coast of the United States and geographic region both are nouns.

Word	Noun	Adjective	Verb	Adverb
East Coast of the United States	Yes	No	No	No
geographic region	Yes	No	No	No

East Coast of the United States (noun)	geographic region (noun)
the eastern seaboard of the United States (especially the strip between Boston and Washington D.C.)	a demarcated area of the Earth