1: a groove running lengthwise on the surface of a cylinder or column
2a: a groove around the cylinder of an elongated bullet for small arms to contain a lubricant
b: a groove around a bullet into which the edge of the cartridge case is crimped
c: a groove around the rotating band of a gun projectile to lessen the resistance offered to the rifling
d: a groove around the base of a cartridge where the extractor takes hold
History and Etymology for cannelure
French cannelure, alteration of Middle French cannelature, from Old Italian cannellatura, probably from cannella small tube, cinnamon, from Medieval Latin canella