All 6 Uses

atrium
in
Queen of Attolia
(Auto-generated)

Inside was an atrium with stairs to the second floor.†
Chpt 9
Eddis stood in the atrium, talking to a man on the balcony above her.†
Chpt 9
"Teleus," she said after a moment, "the Eddisian prisoners are being brought in, either to the atrium or into the megaron itself.†
Chpt 17
She strode up the steps to the entrance to the atrium at the fore of the megaron.†
Chpt 19
THE SENESCHAL OF EPHRATA, THE captain of the guard, several barons both Eddisian and Attolian, and various members of both households waited where the corridor came to the main atrium.†
Chpt 20
The Eddisians were certainly a barbarous lot—no wonder the Mede underestimated them—but they looked quite comfortable waiting at the edge of the atrium.†
Chpt 20 *

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.