sēmĭ-circŭlus

I. semicircular: ager, Col. 5, 2, 8.—Hence, subst.: sēmĭ-circŭlus, i, m., a half-circle, semicircle (syn. semiorbis): uncus in semicirculi speciem, Cels. 7, 26, 2: ager, Col. 5, 2, 8.