Can·non n.; pl. Cannons collectively Cannon.
 1. A great gun; a piece of ordnance or artillery; a firearm for discharging heavy shot with great force.
 Note: ☞ Cannons are made of various materials, as iron, brass, bronze, and steel, and of various sizes and shapes with respect to the special service for which they are intended, as intended, as siege, seacoast, naval, field, or mountain, guns. They always aproach more or less nearly to a cylindrical from, being usually thicker toward the breech than at the muzzle. Formerly they were cast hollow, afterwards they were cast, solid, and bored out. The cannon now most in use for the armament of war vessels and for seacoast defense consists of a forged steel tube reinforced with massive steel rings shrunk upon it. Howitzers and mortars are sometimes called cannon. See Gun.
 2. Mech. A hollow cylindrical piece carried by a revolving shaft, on which it may, however, revolve independently.
 3. Printing. A kind of type. See Canon.
 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.