What is the central opening in the roof over an atrium called?

The central opening in the roof over an atrium is known as the compluvium. This architectural feature is designed to allow light and air to enter the atrium while also providing a means for rainwater to be collected. The water that falls through this opening would typically flow into a basin or pool known as the impluvium, which is situated directly below the compluvium. This clever design not only enhances the aesthetic appeal of the atrium but also contributes to the practical aspects of water collection in a Roman home.

The other terms do not accurately describe the central opening of the atrium. For instance, the imperium refers to the authority or power, often related to military command, while the piscina denotes a fishpond or a bathing area, and the conditorium typically relates to a storage room or pantry, neither of which pertains to the atrium's architectural elements.