K Street Definition
noun
The group of lobbyists who attempt to influence the policies of the US government.
American Heritage
(US, politics, slang) The people and firms that lobby the United States Congress.
Wiktionary
Origin of K Street
After K Street , street in Washington, DC, on which the offices of many lobbying firms are located
From American Heritage Dictionary of the English Language, 5th Edition
After K Street in Washington, D.C.
From Wiktionary