washington
n. uncountablen. the capital city of the United States. People also use this name to talk about the American government or its leaders.
n. the federal capital of the United States of America. Metonymically used to refer to the U.S. federal government or its executive and legislative branches.
The president lives and works in Washington.
Washington announced a new trade policy today that will affect several international partners.
While the city itself is home to diverse neighborhoods, the name Washington is frequently used in political journalism to represent the collective decisions of the federal administration.
Washington (the town in Tyne and Wear, northeast England): probably from the Old English place name Hwæssingatūn (literally “a settlement of the household of Hwæssa”), from Hwæssa (a Saxon chieftain's name) + -ing (“belonging to”) + tūn (“homestead, settlement”). It was attested in 1096 as Wasindone. Hwæssa is of uncertain origin, said to possibly correspond to waþ (“hunt”) + sige (“victory”), or possibly related to hwæte (“wheat”). There are other theories; more on Wikipedia. The surname derives from the town, and most places in the United States are named for George Washington.
When used as a metonym for the government, it functions as a singular noun.