Which of the following is not a characteristic of a vomitory?

The characteristic that is not associated with a vomitory is that it is a part of the stage set. Vomitories are architectural features commonly found in theatres, particularly in ancient Roman and modern amphitheaters, designed primarily to facilitate the movement of the audience in and out of the seating areas. They serve essential functions such as providing emergency exits, directing audience flow, and enhancing accessibility for the audience to enter and exit the venue comfortably.

In contrast, the concept of a vomitory does not pertain to elements that make up the stage or its set design, which typically includes backdrops, props, and other theatrical components intended for performance. Thus, stating that it is a part of the stage set does not accurately describe its purpose, which is more about audience logistics rather than the actual performance space or visual elements of a play.