\Cur"va*ture\ (k?r"v?-t?r; 135), 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.
         The elegant curvature of their fronds. --Darwin.
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.
{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.