Washington D.C.

n. capital city of the United States

Washington, D.C. is the capital of the United States, situated within the District of Columbia (abbreviated as "D.C."). The city and the district are located on the banks of the Potomac River and bordered by the states of Virginia (to the west) and Maryland (to the north, east and south). The city was planned and developed in the late 18th century to serve as the permanent national capital; the federal district was formed to keep the national capital distinct from the states. The city was named after George Washington, the first President of the United States. Columbia in this context is an early poetic name for the United States, a reference to Christopher Columbus, an early European explorer of the Americas. The city is commonly referred to as Washington, The District, or simply D.C. In the 19th century, it was called the Federal City or Washington City.
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Noun
1. the capital of the United States in the District of Columbia and a tourist mecca; George Washington commissioned Charles l'Enfant to lay out the city in 1791
(synonym) Washington, American capital, capital of the United States
(hypernym) national capital
(hyponym) Potomac, Foggy Bottom
(part-holonym) District of Columbia, D.C., DC
(part-meronym) Capitol, Capitol Building