Potomac and Potomac River

Potomac noun - 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.

Potomac River and Potomac are semantically related. In some cases you can use "Potomac River" instead a noun "Potomac".

Potomac River noun - 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.

Potomac and Potomac River are semantically related. You can use "Potomac" instead a noun phrase "Potomac River".