Topic summary
Guest star
Extracted from the Wikipedia article Guest appearance.
TV series and video games
In a TV series, a guest star is an actor who appears in one or a few episodes (sometimes a story arc). In some cases a guest star may play an important recurring character and may appear many times in a series, despite not being a member of the main cast; they may ultimately be asked to join the main cast if their role continues. The title special guest star is typically used in television for a celebrity guest, but it is also occasionally used for a regular cast member—usually for an actor or actress who is featured heavily but joined the show after the rest of the cast was signed.