I.a round shape, roundness, rotundity (post-Aug.).
I. Lit.: “gemma rotunditatis absolutae,” Plin. 37, 11, 73, § 190; so id. 18, 13, 34, § 130; 16, 23, 35, § 86; 19, 5, 25, § 76 al.—
II. Trop.: “verborum,” a roundness, smoothness, Macr. S. 7, 5: “Symmachi,” Sid. Ep. 1, 1.—Concr., a circular space: “rotunditas dimidii cubiti,” Vulg. 3 Reg. 7, 35.