landing flap

noun
  1. a flap in the undersurface of the trailing edge of an aircraft wing, capable of being moved downward to increase either lift or drag or both, as for landing.Compare split flap(def 1).

Origin of landing flap

First recorded in 1935–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018