Central Intelligence Agency, CIA - an independent agency of the United States government responsible for collecting and coordinating intelligence and counterintelligence activities abroad in the national interest; headed by the Director of Central Intelligence under the supervision of the President and National Security Council

intelligence agency, intelligence service, intelligence - a unit responsible for gathering and interpreting information about an enemy

Defense Intelligence Agency, DIA - an intelligence agency of the United States in the Department of Defense; is responsible for providing intelligence in support of military planning and operations and weappons acquisition

National Reconnaissance Office, NRO - an intelligence agency in the United States Department of Defense that designs and builds and operates space reconnaissance systems to detect trouble spots worldwide and to monitor arms control agreements and environmental issues and to help plan military operations

National Security Agency, NSA - the United States cryptologic organization that coordinates and directs highly specialized activities to protect United States information systems and to produce foreign intelligence information

Secret Service, SS, United States Secret Service, US Secret Service, USSS - the United States intelligence agency that protects current and former presidents and vice presidents and their immediate families and protects distinguished foreign visitors; detects and apprehends counterfeiters; suppresses forgery of government securities and documents