A pseudonym is a false name, sometimes a joke name. Pseudonyms are used to disguise identity. A pseudonym isn't, however, a 'literary name' as in Chinese, or a 'pen name' in Western literature, which have different connotations. A pseudonym can be a complete false identity, including operation of a business identity and transactions in that name. Also known as an 'alias', in many countries even use of pseudonyms is illegal.