Source : Webster's Revised Unabridged Dictionary (1913)

Cannelure \Can"ne*lure\ (k[a^]n"n[-e]*l[-u]r), 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.