Lewis & Short

curvātūra, ae, f. [curvo], a bending, rounding, bend (not ante-Aug.).

  1. I. Abstr., Vitr. 2, 8, 11; Plin. 2, 17, 14, § 72; 10, 19, 21, § 42 al.
  2. II. Concr., a vault: camerae, an arched ceiling, Vitr. 7, 3: rotae, i. e. the rim, Ov. M. 2, 108.