the flexure of a curve

Flexure \Flex"ure\ (?; 135), n. [L. flexura.]
   1. The act of flexing or bending; a turning or curving;
      flexion; hence, obsequious bowing or bending.
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            Will it give place to flexure and low bending?
                                                  --Shak.
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   2. A turn; a bend; a fold; a curve.
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            Varying with the flexures of the valley through
            which it meandered.                   --British
                                                  Quart. Rev.
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   3. (Zool.) The last joint, or bend, of the wing of a bird.
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   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.
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   {The flexure of a curve} (Math.), the bending of a curve
      towards or from a straight line.
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