windage

UK: /ˈwɪndɪdʒ/ US: (win′dij)

WordReference Random House Unabridged Dictionary of American English © 2025

wind•age  (win′dij), n. 

1. Rocketry the influence of the wind in deflecting a missile.
2. Rocketry the amount of such deflection.
3. the degree to which a gunsight must be adjusted to correct for windage.
4. a difference between the diameter of a projectile and that of the gun bore, for the escape of gas and the prevention of friction.
5. Nautical that portion of a vessel's surface upon which the wind acts.
6. Mechanical Engineering [Mach.] friction between a rotor and the air within its casing, as in an electric generator.
7. Electricity the resisting influence of air against the rotating armature of a dynamo, creating a power loss.

• wind¹ + -age 1700–10

Collins Concise English Dictionary © HarperCollins Publishers::

windage / ˈwɪndɪdʒ/ noun

1. a deflection of a projectile as a result of the effect of the wind
2. the degree of such deflection
3. the extent to which it is necessary to adjust the wind gauge of a gun sight in order to compensate for such deflection
4. the difference between a firearm's bore and the diameter of its projectile
5. the exposed part of the hull of a vessel responsible for wind resistance
6. the retarding force upon a rotating machine resulting from the drag of the air