What does within mean in romeo and Juliet?

"Within" means "within" at all times; it is a modern English Word that is used every day by English speakers, although it is more common in written English. If, for some reason, you have not run across it before, it means about the same thing as "inside". In a stage direction (such as "Nurse (within): Madam!") it means that the person is offstage ("within" or "inside" the house represented by the back wall of the stage).