windage

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The effect of wind on the course of a projectile.
2. n. The point or degree at which the wind gauge or sight of a rifle or gun must be set to compensate for the effect of the wind.
3. n. The difference in a given firearm between the diameter of the projectile fired and the diameter of the bore of the firearm.
4. n. The disturbance of air caused by the passage of a fast-moving object, such as a railway train.
5. n. Nautical The part of the surface of a ship exposed to the wind.

Century Dictionary and Cyclopedia

1. n. The disturbance of the atmosphere by the movement of any object through it, as by that of a revolving fly-wheel or armature.
2. n. The space intervening between the moving part of any mechanism and the inclosure within which it moves, as the air-gap of a dynamo.
3. n. The air-friction of the moving parts of a machine as distinguished from the friction of the bearing surfaces.
4. n. In gunnery:
5. n. The difference allowed between the diameter of a projectile and that of the bore of the gun from which it is to be fired, in order to allow the escape of some part of the explosive gas, and to prevent too great friction.
6. n. The rush or concussion of the air produced by the rapid passage of a shot.
7. n. The influence of the wind in deflecting a missile, as a ball or an arrow, from its direct path, or aside from the point or object at which it is aimed; also, the amount or extent of such deflection.
8. n. The play between the spindle of the De Bange gas-cheek and its cavity in the breech-screw: it is expressed in decimal parts of an inch, and is measured by the difference between the diameters of the spindle and its cavity.
9. n. In surgery, same as wind-contusion.

Wiktionary

1. n. automotive Drag on the crankshaft caused by oil splashing out of the sump when rotating at high speeds.
2. n. ballistics The difference in diameter between the bore of a firearm and the shot
3. n. ballistics Horizontal adjustment of the sight of a firearm
4. n. medicine, dated A contusion caused by a projectile that does not enter the skin, due to either compressed air or a glancing blow
5. n. Exposure to the wind

GNU Webster's 1913

1. n. (Gun.) The difference between the diameter of the bore of a gun and that of the shot fired from it.
2. n. The sudden compression of the air caused by a projectile in passing close to another body.

WordNet 3.0

1. n. the deflection of a projectile resulting from the effects of wind
2. n. the retarding force of air friction on a moving object
3. n. the space between the projectile of a smoothbore gun and the surface of the bore of the gun
4. n. exposure to the wind (as the exposed part of a vessel's hull which is responsible for wind resistance)