A pseudonym or alias is a fictitious name that a person assumes for a particular purpose, which differs from their original or true name (orthonym). This also differs from a new name that entirely or legally replaces an individual's own. Many pseudonym holders use them because they wish to remain anonymous, but anonymity is difficult to achieve and often fraught with legal issues.

A ring name is a type of stage name used by an athlete such as a professional wrestler, mixed martial artist, or boxer whose real name is considered unattractive, dull, difficult to pronounce or spell, amusing for the wrong reasons, or projecting the wrong image. Since the advent of the Internet, it is relatively easy to discover a fighter's real name.