East Coast of the United States vs geographic area

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

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

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