A swivel gun is a type of small cannon that was typically mounted on a swiveling mount or platform. There are several synonyms that are used to describe this type of weapon. One common alternate term is a "swivel cannon," which refers to the gun's ability to rotate or swivel on its mount. Another name for a swivel gun is a "pivot gun," which emphasizes the weapon's ability to pivot or turn in any direction. A "breechloader" is another term that can be used to describe a swivel gun, as this type of cannon typically loaded from the rear rather than the front. Finally, the term "deck gun" can be used to describe a swivel gun that is mounted on a ship's deck and used to defend against other vessels.