'Windage' definitions:

Definition of 'windage'

(from WordNet)
noun
The retarding force of air friction on a moving object
noun
The space between the projectile of a smoothbore gun and the surface of the bore of the gun
noun
Exposure to the wind (as the exposed part of a vessel's hull which is responsible for wind resistance) [syn: windage, wind exposure]
noun
The deflection of a projectile resulting from the effects of wind [syn: windage, wind deflection]

Definition of 'Windage'

From: GCIDE
  • Windage \Wind"age\, n. [From Wind air in motion.] [1913 Webster]
  • 1. (Gun.) The difference between the diameter of the bore of a gun and that of the shot fired from it. [1913 Webster]
  • 2. The sudden compression of the air caused by a projectile in passing close to another body. [1913 Webster]