Windage

Wind′age

,

Noun.

[From

air in motion.]

1.

(Gun.)

The difference between the diameter of the bore of a gun and that of the shot fired from it.

2.

The sudden compression of the air caused by a projectile in passing close to another body.

,

Noun.

The difference between the diameter of a piece and that of a ball or shell.

windage ‎(usually uncountable, plural windages)

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