The area of the stage setting within which the actor performs. It may include areas off the normal stage.(UK) Usually split into theoretical portions for ease of reference. 
The area of the stage where the play is performed. Also called the Playing Area.
the part of a stage used by the actors: Confine the acting area for this scene to downstage.
That area within the performance space within which the actor may move in full view of the audience. Also known as the playing area.