Know how to use "fewer" and "less"? Find out.
1660s, from Latin curvatura "a bending," from curvatus, past participle of curvare "to bend" (see curve (v.)). In non-Euclidian geometry, from 1873.
curvature cur·va·ture (kûr'və-chur', -chər)n. A curving or bending, especially an abnormal one.