(Latin, he goes out). A theatrical term placed at the point when an actor is to leave the stage. We also say of an actor, Exit So-and-so—that is, So-and-so leaves the stage at this point of the drama.
All the world's stage, And all the men and women merely players; They have their exits and their entrances.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894