1. The action or behavior of an airplane (or one of its airfoils) when by the separation of the airflow, as in the case of insufficient airspeed or of an excessive angle of attack, the airplane or airfoil tends to drop; the condition existing during this behavior.

2. A flight performance in which an airplane is made to lose flying speed and to drop by pointing the nose steeply upward.

3. An act or instance of stalling.