flexure

noun

1. 1.The act of bending or flexing; flexion.
2. 2.A turn; a bend; a fold; a curve.
3. 3.A curve or bend in a tubular organ.
4. 4.The last joint, or bend, of the wing of a bird.
5. 5.The small distortion of an astronomical instrument caused by the weight of its parts; the amount to be added or subtracted from the observed readings of the instrument to correct them for this distortion.