Flexure /(?; 135)/

Flex·ure

Flexure

n.
  1. The act of flexing or bending; a turning or curving; flexion; hence, obsequious bowing or bending.
    Will it give place to flexure and low bending?
  2. A turn; a bend; a fold; a curve.
    Varying with the flexures of the valley through which it meandered.
    — British Quart. Rev.
  3. The last joint, or bend, of the wing of a bird. (Zool.)
  4. The small distortion of an astronomical instrument caused by the weight of its parts; the amount to be added or substracted from the observed readings of the instrument to correct them for this distortion. (Astron.)

Phrases & Compounds
The flexure of a curve
the bending of a curve towards or from a straight line.