What is "wing warping"

n. # (context aviation historical English) an early system for lateral (roll) control on a fixed-wing aircraft, involving the flexing of the wing to achieve movement.

Wing warping was an early system for lateral (roll) control of a fixed-wing aircraft. The technique, used and patented by the Wright brothers, consisted of a system of pulleys and cables to twist the trailing edges of the wings in opposite directions. In many respects, this approach is similar to that used to trim the performance of a paper airplane by curling the paper at the back of its wings.

Many birds use wing warping to achieve control. This was a significant influence on early aircraft designers.