Definitions

1. adverb

in or into a theater or other performance area, especially on a stage

“The actor was always on stage, even when the play was over.”

2. noun

the part of a theater or other performance area where a play, concert, or other performance is given

“The audience watched the play from the audience, but the actors were on stage.”

3. preposition

in or into a theater or other performance area, especially on a stage

“The actors were on stage when the fire alarm went off.”