Flexure

n.
  1. The act of flexing or bending; a turning or curving; flexion; hence, obsequious bowing or bending.
  2. A turn; a bend; a fold; a curve.
  3. (Zoöl.) The last joint, or bend, of the wing of a bird.
  4. (Astron.) 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.
  5. The flexure of a curve (Math.),
    the bending of a curve towards or from a straight line.