Plain English Meaning
The shape of the top of the wing — specifically how curved it is from front to back. On most wings, the top is more rounded than the bottom, and that difference helps the wing produce lift.
Full Definition
The curved upper surface of an airfoil, measured as the curvature of the top of the wing from the leading edge to the trailing edge. The upper camber is typically more curved than the lower surface, and this asymmetry is one of the factors that produces lift as air flows over the wing.
Context Anchor
Seen in wing and airfoil diagrams when learning how the shape of a wing affects airflow and lift.