windage (Noun) — The retarding force of air friction on a moving object.
windage (Noun) — The space between the projectile of a smoothbore gun and the surface of the bore of the gun.
windage (Noun) — Exposure to the wind (as the exposed part of a vessel's hull which is responsible for wind resistance).
windage (Noun) — The deflection of a projectile resulting from the effects of wind.