Old Dominion State vs Potomac

Old Dominion State and Potomac both are nouns.

Word	Noun	Adjective	Verb	Adverb
Old Dominion State	Yes	No	No	No
Potomac	Yes	No	No	No

Old Dominion State (noun)	Potomac (noun)
a state in the eastern United States; one of the original 13 colonies; one of the Confederate States in the American Civil War	term sometimes used to refer to Washington, D.C.
	a river in the east central United States; rises in West Virginia in the Appalachian Mountains and flows eastward, forming the boundary between Maryland and Virginia, to the Chesapeake Bay