The "fourth wall" is a term used in theatre and film to describe the imaginary barrier between the actors/characters and the audience/viewers. There are several synonyms for this term, including "invisible wall", "behind the scenes barrier", "dramatic screen", "performance divide", and "audience partition". These phrases all convey the idea that there is a separation between the performers and the audience, and that the audience is observing the action from a distance. However, the specific phrase used may depend on the context in which it is being used or the preference of the speaker or writer. Ultimately, these synonyms all serve to describe the same concept of the "fourth wall".