All 6 Uses

atrium
in
Nineteen Minutes
(Auto-generated)

There was a new green metal roof, fresh grass growing out front, and a glass atrium that rose two stories at the rear of the school.†
Chpt 2
Instead, now, there was an enormous glass atrium that covered the spot where the gymnasium and locker room had been.†
Chpt 2 *
To one side of the atrium, in front of the glass wall, were ten chairs.†
Chpt 2
Unlike the rest of the seats in the atrium, these had backs and were painted white.†
Chpt 2
She noticed that the maple tree, the one that had grown outside the window of the second-story locker room, had not been cut down during the construction of the atrium.†
Chpt 2
They walked out of the atrium in silence, down the corridors, past the rows of cubbies.†
Chpt 2

Definitions:

(1) (atrium as in: atrium of the building)
a central open space in a building -- often a large skylit hall near the entrance

In ancient Roman houses and early Christian churches, an atrium was an open courtyard. In many modern buildings, it is an indoor space that may include plants, water features, and balconies or walkways to other rooms.
(2) (atrium as in: right atrium of the heart)
chamber from which blood enters the heart
(3) (meaning too rare to warrant focus)
Much less commonly, atrium can refer to anatomical structures other than the heart.