"OSS" stands for Office of Strategic Services, an American federal agency formed in 1942 that was the precursor to the modern-day Central Intelligence Agency (CIA). As of 2014, the OSS is no longer in operation.
The Office of Strategic Services began as part of the Coordinator of Information office that was formed in 1941. As World War I began, President Roosevelt and military leaders decided to split the COI into two agencies: the Foreign Information Service and the OSS. The OSS was responsible for conducting espionage in enemy territory, collecting and analyzing information about the war and performing operations not assigned to various branches of the Armed Forces.