lift-drag ratio

(aerospace engineering) The lift of an aerodynamic form, such as an airplane wing, divided by the drag.

The magnitude of lift force divided by the magnitude of total drag forces acting on a body at any given time as it moves through a fluid. The lift-drag ratio is affected by the angle of attack. When throwing a projectile such as a discus or javelin, the optimum angle of attack for maximizing performance is the angle at which the lift-drag ratio is maximum.