noun

atrium

AY-tree-um/ˈeɪtriəm/

An open central space or courtyard within a building.

Sunlight fills the hotel's central atrium through a glass roof.

A simple architectural view of a modern building’s spacious open central atrium, with upper-floor galleries surrounding the central void and a glass skylight above.

Etymology

Latin atrium named the central court or main room of a house, which contained the hearth. The modern sense preserves that central interior space, often lit from above.

In context

A&E2:44

I was the first one in and I could see an open-air atrium. And on the other side of that atrium, there was a lot of fire.

Arson Fire Kills Firefighter, But It Was No Accident (S2, E23) | Cold Case Files | Full Episode

More examples

Visitors gathered around the fountain in the atrium.
The two office towers each have spacious atria.
Plants surround the seating area in the atrium.

Forms

atrium · atria · atriums

Similar words

courtyard: Usually means an outdoor space enclosed by buildings or walls.
lobby: Is primarily an entrance and reception area, not necessarily central.