Lewis Short
curvātūra (noun F) : id.
* A bending, rounding, bend (not ante-Aug.).
* Abstr., Vitr. 2, 8, 11; Plin. 2, 17, 14, § 72; 10, 19, 21, § 42 al.
* Concr., a vault: camerae,an arched ceiling,Vitr. 7, 3: rotae,i. e. the rim,Ov. M. 2, 108.
Charlton T. Lewis, Charles Short, A Latin Dictionary