Plain English Meaning
When wind is blowing from the side, the airplane gets pushed off the line you want to fly. To fix this, you point the nose a little into the wind so that the combined effect of the airplane moving forward and the wind pushing sideways still carries you along your intended path.
Full Definition
The technique of compensating for a crosswind by turning the airplane's nose slightly into the wind so that the airplane's actual path over the ground follows the intended track, rather than being pushed sideways off course.
Context Anchor
Used during straight-and-level flight when outside references show the airplane is sliding sideways across the ground instead of staying on the desired path.
Derivation
' comes from the Old Norse and Middle English sense of being carried along by a — the same word used for or a boat drifting on . In it means being carried sideways by the wind. 'Correcting' simply means making an adjustment to fix it.