- the branch of governmental service that conducts secret investigations, especially investigations into the military strength of other nations.
- (initial capital letters) the branch of the U.S. Department of the Treasury charged chiefly with the discovery and apprehension of counterfeiters and with providing protection for the president and the president’s immediate family.
- secret work for a government, especially espionage.
- a government agency or department that conducts intelligence or counterintelligence operations
- such operations
- a US government agency responsible for the protection of the president, the suppression of counterfeiting, and certain other police activities
A division of the United States Department of the Treasury, responsible for apprehending counterfeiters; investigating a variety of federal crimes; and protecting presidents and their families, presidential candidates, and foreign dignitaries visiting the United States.