1. A small vertical wing or similar device at the end of a wing, used to reduce drag on a fixed-wing aircraft
   "The new aircraft design incorporated winglets to improve fuel efficiency"
    
2. A small wing-like projection, especially one attached to the wingtip of an aircraft to improve aerodynamic efficiency
   "The new aeroplane design incorporated winglets to reduce fuel consumption"

Derived forms: winglets

Encyclopedia: Winglet