Definition of waiver. 1  1 : the act of intentionally relinquishing or abandoning a known right, claim, or privilege; also : the legal instrument evidencing such an act.
Roll, pitch and yaw. Roll, pitch and yaw are rotations along the natural axes of the helicopter (or any aircraft). A rolling movement is where the helicopter rotates along a line along its length using lateral cyclic inputs (aileron), eventually turning from right way up to inverted while maintaining the helicopter's heading.
The yaw axis is perpendicular to the wings and lies in the plane of the aircraft centerline. A yaw motion is a side to side movement of the nose of the aircraft as shown in the animation. The yawing motion is being caused by the deflection of the rudder of this aircraft. The rudder is a hinged section at the rear of the vertical stabilizer. As described on the shape effects slide, changing the angle of deflection at the rear of an airfoil changes the amount of lift generated by the foil.