Plain English Meaning
A wing that is wider where it joins the airplane and narrows toward the tip, rather than being the same width along its whole length.
Full Definition
A wing planform whose chord (the distance from leading edge to trailing edge) decreases gradually from the wing root to the wingtip, producing a wing that is wider where it meets the fuselage and narrower at the tip. A tapered wing offers a useful compromise between the structural simplicity of a rectangular wing and the aerodynamic efficiency of an elliptical wing, with reduced drag and weight compared to a rectangular wing of the same area.