HEMICYCLE

Hem″i‐cy′cle (?), n. [[L. hemicyclus, Gr. �; � + �.]] 1. 1. A half circle; a semicircle.
2. 2. A semicircular place, as a semicircular arena, or room, or part of a room.
The collections will be displayed in the hemicycle of the central pavilion. London Academy.