- A weapon which throws or propels a missile to a distance; any firearm or instrument for throwing projectiles by the explosion of gunpowder, consisting of a tube or barrel closed at one end, in which the projectile is placed, with an explosive charge behind, which is ignited by various means. Muskets, rifles, carbines, and fowling pieces are smaller guns, for hand use, and are called small arms. Larger guns are called cannon, ordnance, fieldpieces, carronades, howitzers, etc. See these terms in the Vocabulary.
- A piece of heavy ordnance; in a restricted sense, a cannon.