Plain English Meaning
A stall that happens when a pilot pushes too much rudder one way and holds the wings level (or tries to) with opposite aileron during a turn -- usually trying to tighten a turn onto final approach. The inside wing stalls first and drops fast, which can flip the airplane toward the ground.
Full Definition
A stall that occurs in a skidding turn when the pilot uses excessive rudder in the direction of the turn while applying opposite aileron to keep the bank angle from steepening, typically while overshooting the final approach course. The mismatched control inputs increase the angle of attack on the inside (lowered) wing, which stalls first and drops sharply, often producing a rapid toward the inside of the turn at .