Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
curvature [ˈkəːvətʃər] n (of the earth) кривизна́; (of curve) изги́б; (of spine) искривле́ние
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: