noun
( -s )
Etymology: from gerund of rifle (IV)
1. : the act or process of making spiral grooves (as in a gun barrel)
2.
a. : a system of spiral grooves cut in the surface of the bore of a gun leaving intervening lands that cut into the projectile when fired or into a metal band secured to it and rotate it about its longer axis
b. : a system of spiral grooves (as in a pipe or drill core)