-incurvature-

n. [ L. curvatura. See Curvate. ] 1. The act of curving, or the state of being bent or curved; a curving or bending, normal or abnormal, as of a line or surface from a rectilinear direction; a bend; a curve. Cowper. [ 1913 Webster ]

The elegant curvature of their fronds. Darwin. [ 1913 Webster ]

2. (Math.) The amount of degree of bending of a mathematical curve, or the tendency at any point to depart from a tangent drawn to the curve at that point. [ 1913 Webster ]

Aberrancy of curvature (Geom.), the deviation of a curve from a circular form. --
Absolute curvature. See under Absolute. --
Angle of curvature (Geom.), one that expresses the amount of curvature of a curve. --
Chord of curvature. See under Chord. --
Circle of curvature. See Osculating circle of a curve, under Circle. --
Curvature of the spine (Med.), an abnormal curving of the spine, especially in a lateral direction. --
Radius of curvature, the radius of the circle of curvature, or osculatory circle, at any point of a curve. [ 1913 Webster ]