A false name under which someone hides their true identity.
The CIA glossary defines an alias as an invented name that conceals a person’s true identity and purpose. Related concepts are cover (a false identity or explanation) and legend (an invented life story backed by documents).1,2
An example from the FBI files: FBI agent Robert Hanssen, who spied for the KGB and later the SVR from 1985 until his arrest in 2001, used the pseudonym “Ramon” in his dealings with Russian officers (in the FBI’s account, also “Ramon Garcia”).3
In its announcement of 28 June 2010 of the arrest of ten people accused of carrying out long-term, “deep-cover” assignments on behalf of Russia, the US Department of Justice presented some of them under assumed names, with the words “known as”. The Department stressed that the charges were, at that stage, only allegations.4
Sources
- CIA, Spy Speak Glossary
- International Spy Museum (Washington, DC), Language of Espionage (glossary)
- FBI, Famous Cases: Robert Hanssen
- US Department of Justice, Ten Alleged Secret Agents Arrested in the United States (press release), 28.06.2010
Checked: 4 November 2026