A pseudonym or allonym is a name, (sometimes legally adopted, sometimes purely fictitious), used by an individual as an alternative to their birth name.
When used by authors, a pseudonym is also called a pen name or (in French) nom de plume. This is an English expression: in France, such an alias is more commonly termed a nom de guerre, or "name of war".
Famous pseudonyms of people who were neither authors nor actors include:
- Le Corbusier, the architect, was Charles Edouard Jeanneret.
- Alan Smithee was the name used by directorss who disown their own movie.
- David Agnew is used on BBC programmes where a writer's name cannot used for contractual reasons.
- Nicolas Bourbaki was a famous pseudonym for a group of mathematicians
- Student was William Sealey Gosset, discoverer of Student's t-distribution in statistics.
- Carlos the Jackal is the nom de guerre of Ilich Ramirez Sanchez, a terrorist
- Hambali is Riduan Isamuddin, the leader of Jemaah Islamiah, a terrorist group; he was born Encep Nurjaman
- Abu Mazen is Mahmoud Abbas, the former prime minister of the State of Palestine
- Abu Ammar was PLO leader Yasser Arafat's nom de guerre, although this name is no longer widely used
- Abu Ala is the name that Ahmed Qurei uses