hēmĭcyclium, ĭi, n., = ἡμικύκλιον,
I a half-circle , semicircle , Vitr. 9, 8, 5; Plin. Ep. 5, 6, 33.—
II In partic.
A A semicircular recess , with seats , Cic. Lael. 1, 2; Sid. Ep. 2, 2.—
B A semicircular public place furnished with rows of seats for learned discussions , Suet. Gramm. 17.—
C A semicircular kind of sundial , Vitr. 9, 8, 1.