Definition
A deliberate decrease in the angle of incidence from the wing root toward the wing tip. The tip is rigged at a smaller angle to the relative wind than the root, so the root reaches the stalling angle of attack before the tip does.
Plain English
The wing is built so that the outer end meets the air at a slightly flatter angle than the inner end. This makes the inner part of the wing stall first, while the outer part keeps flying.
Context Anchor
Seen in aircraft design, maintenance, wing inspection, and discussions of stall behavior.
Derivation
From the engineering sense of "washing out" meaning to gradually reduce or taper away. The angle of incidence is tapered down as you move outboard along the wing.
Why Pilots Care
Gives the pilot continued aileron control and more predictable handling as a stall develops.
Analogy
Think of holding a flat board and giving it a very slight twist so one end is angled less than the other. A wing with Wash-Out has that kind of twist built into its shape.
Intuition Check
Wash-Out does not mean something was cleaned away or ruined. Here it means a deliberate twist in the wing that reduces the wing’s angle toward the tip.
Example Sentence 1
Most training aircraft are built with wash-out so the ailerons remain effective as the wing approaches the stall.
Example Sentence 2
Wash-out helps keep the ailerons effective longer during a slow approach to stall.