All 7 Uses of

atrium
in
Allegiant

I reach the end of one hallway and find myself in an atrium, surrounded by the smell of wet earth.†
p. 139.2

I find myself in the atrium garden again, and this time, light glows behind the windows.†
p. 332.7

Cara jogs into the atrium, her hair askew and floating over her forehead.†
p. 332.8

Tobias takes me to the atrium near the hotel dormitory, and we spend some time there, talking and kissing and pointing out the strangest plants.†
p. 430.5

I stand on the higher step in the atrium and he stands on the lower one, so we're on the same plane.†
p. 431.3 *

Most of the time I can tell when people are lying, and this must be a lie, because Tris is still alive, her eyes bright and her cheeks flushed and her small body full of power and strength, standing in a shaft of light in the atrium.†
p. 490.1

Definitions:

(1) (atrium as in: atrium of the building)
a large public room leading to other rooms--often skylit and containing plants and/or water features

or in ancient architecture:

a roofless area of a building--such as the center of a Roman house or an entry courtyard surrounded by roofed columns in an ancient Christian church
(2) (atrium as in: right atrium of the heart)
chamber from which blood enters the heart
(3) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Much less commonly, atrium can refer to anatomical structures other than the heart.