Cannon ball, strictly, a round solid missile of stone or iron made to be fired from a cannon, but now often applied to a missile of any shape, whether solid or hollow, made for cannon. Elongated and cylindrical missiles are sometimes called bolts; hollow ones charged with explosives are properly called shells. -- Cannon bullet, a cannon ball. [Obs.] -- Cannon cracker, a fire cracker of large size. -- Cannon lock, a device for firing a cannon by a percussion primer. -- Cannon metal. See Gun Metal. -- Cannon pinion, the pinion on the minute hand arbor of a watch or clock, which drives the hand but permits it to be moved in setting. -- Cannon proof, impenetrable by cannon balls. -- Cannon shot. (a) A cannon ball. (b) The range of a cannon.