secret service
noun /ˌsiːkrət ˈsɜːvɪs/
/ˌsiːkrət ˈsɜːrvɪs/
[usually singular]- a government department that is responsible for protecting its government’s military and political secrets and for finding out the secrets of other governments
（政府的）特工部门，特务机关 CultureThe Secret Service or the United States Secret Service is a division of the US Department of Homeland Security responsible for protecting the President and his or her family. It also guards the Vice-President, former Presidents and major political candidates for President. It was originally set up to investigate and arrest people who printed false money and it still has the task of investigating financial crime. Its present duties began in 1901 after President William McKinley was murdered. see also Allan Pinkerton