Which term refers to a small hidden trap door at stage level containing electrical outlets?

The term that specifically refers to a small hidden trap door at stage level containing electrical outlets is a "trap." A trap is a special feature in stage design that allows for items or performers to enter or exit the stage discreetly. It can also house electrical outlets for the convenience of stage technicians and lighting designers, helping to manage power needs without cluttering the performance area.

The other terms listed have different meanings in a theatrical context.

• A dip might refer to a slight depression or change in the stage level but does not specifically indicate a hidden door or electrical features.

• A grid refers to the framework above the stage from which lights and other equipment are hung. It is essential for rigging but does not deal with stage-level access points.

• A cove typically describes a curved or angled surface in the theater, often used in lighting design to diffuse stage lighting, but it does not refer to a trap door at stage level.

Thus, "trap" is the correct term to use in this context when discussing a hidden access point at stage level that also accommodates electrical outlets.