Plain English Meaning

The cushion you keep between how the airplane is flying right now and the point where something bad would happen. The bigger the cushion, the more room you have to react if something changes.

Full Definition

The buffer of airspeed, altitude, or aircraft performance held in reserve above the minimum required to keep the airplane flying safely under current conditions. In stall awareness, it specifically refers to the airspeed cushion above stall speed that protects the airplane from an inadvertent stall during maneuvering, configuration changes, or gusty conditions.

Context Anchor

You will see this term in stall awareness, slow flight, approach, and maneuvering discussions, especially when the is explaining why a should avoid flying too close to conditions.