Rifling
Pronunciation : Ri"fling, n. (a) The act or process of making the grooves in a rifled cannon or gun barrel. (b) The system of grooves in a rifled gun barrel or cannon. Shunt rifling, rifling for cannon, in which one side of the groove is made deeper than the other
Part of Speech : to
Definition :
facilitate loading with shot having projections which enter by the deeper part of the grooves.
Source : Webster's Unabridged Dictionary, 1913