mononym

A mononym is a one-word name, like Madonna or Socrates. These days, most mononyms are adopted by people who were given at least two names when they were born.

Early in his music career, Prince Rogers Nelson decided to change his name to a mononym, and he became famous as Prince. Other celebrities are widely known by a mononym, despite no official change to a single-word name; this is common for athletes, Bollywood stars, and artists. Egyptian pharaohs, Biblical figures, and ancient Greeks all had mononyms (think Tutankhamun, Eve, and Homer). The word mononym derives from Greek roots, monos, "single," and onoma, "name."