the shape of, or the angle formed by, an airplane wing or other airfoil the leading or trailing edge of which slopes backward from the fuselage.
Origin of sweepback
First recorded in 1915–20; noun use of verb phrase sweep back
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
the rearward inclination of a component or surface, such as an aircraft wing, fin, etc