Plain English Meaning
Pulling, pushing, or rolling the airplane hard enough that the forces on the airframe go past what the airplane was built to handle. The wings, tail, and structure can bend, deform, or break.
Full Definition
Subjecting an airplane's structure to aerodynamic loads that exceed its certified design limits, typically expressed in G-units (load factor). This usually occurs through abrupt or excessive control inputs, particularly during recovery from an upset, that produce loads beyond the limit load factor for which the airframe was certified.
Context Anchor
Encountered in upset prevention and recovery training, especially when learning to recover smoothly without pulling too hard or building too much airspeed.