Definition
A wing whose leading edge angles rearward from the wing root toward the wingtip, so the tips are positioned aft of the point where the wing joins the fuselage. Sweepback delays the onset of compressibility effects at high subsonic speeds and improves directional stability, at the cost of reduced low-speed lift and a tendency for the wingtips to stall before the wing root.
Plain English
A wing that angles backward from where it meets the fuselage out to the tips, instead of sticking straight out to the sides.
Context Anchor
Seen when discussing aircraft design, high-speed airplanes, jet aircraft, and how wing shape affects flight characteristics.
Derivation
Swept (past tense of sweep, from Old English swāpan, to move in a wide curve) plus back. The wing looks as though it has been swept rearward from its root, like hair pushed back from the forehead.
Why Pilots Care
Allows safe flight at higher speeds by delaying the formation of shock waves and reducing wave drag.
Analogy
From above, a sweptback wing looks a little like two arms angled backward instead of stretched straight out to the sides.
Intuition Check
A sweptback wing is not a wing that has been pushed or bent backward in flight. It is built with a backward angle as part of the aircraft’s design.
Example Sentence 1
The airliner's sweptback wing allows it to cruise efficiently at high subsonic speeds without encountering shock wave problems.
Example Sentence 2
Maintenance records noted the sweptback wing configuration on the training aircraft.