winglet

Imagine an airplane soaring through the sky. Now look at the ends of its wings. On many planes, you will notice a small extension rising upward, angled outward, or shaped smoothly into the tip. That part is called a winglet. It is not just decorative; it helps the aircraft fly more efficiently. Winglets reduce "wingtip vortices," the swirling air that forms at the end of a wing and creates drag. By weakening those vortices, they reduce resistance and help the plane use less fuel.

The idea became widely known through Richard Whitcomb's work in the 1970s, and winglets are now common in modern aircraft design. There are different kinds. Blended winglets curve smoothly into the wing, while split-tip designs have two fin-like parts. You can find them on airliners such as the Boeing 737 and Airbus A320, as well as on business jets and some smaller private aircraft.

The word is used mostly in aviation. In rare cases, it can also mean a small wing-like part on another object, but that use is much less common. In everyday English, when someone says "winglet," they almost always mean the fuel-saving extension at the tip of an airplane wing.