Cannelure

n. [ F., fr. canneler to groove. ] (Mil.) A groove in any cylinder; specif., a groove around the cylinder of an elongated bullet for small arms to contain a lubricant, or around the rotating band of a gun projectile to lessen the resistance offered to the rifling. Also, a groove around the base of a cartridge, where the extractor takes hold. -- Can"ne*lured a. [Webster 1913 Suppl.]