Plain English Meaning

How hard the wings are working to hold the aircraft up at a given moment. In straight and level flight the wings just carry the aircraft's weight. In a steep turn or a pull-up, the wings have to lift much more than that, so the load on them goes up.

Full Definition

The total aerodynamic load that the wings must support at any given moment, expressed as the lift the wings are producing relative to the aircraft's weight. In a level, unaccelerated flight the wings carry a load equal to the aircraft's weight, but in a turn or pull-up the wings must produce more lift, so the aerodynamic wing loading increases. It is commonly expressed as a load factor (G).

Context Anchor

Seen in steep turn discussions when explaining why load factor and stall speed increase as increases.