Plain English Meaning
The airplane is no longer flying the way the pilot wants it to, and the pilot cannot bring it back to normal controlled flight in time.
Full Definition
An in-flight event in which the airplane departs from its intended flight path and the pilot is unable to keep it within the limits required for safe, controlled flight. It typically involves the airplane exceeding its normal flight parameters such as pitch, bank, airspeed, or load factor, often leading to a stall, spin, or unrecoverable upset.
Context Anchor
Seen in accident prevention, stall awareness, , and airplane discussions.