Siege weapon in the context of "Siege gun"

The 12-pounder long gun was an intermediary calibre piece of artillery mounted on warships of the Age of Sail. They were used as main guns on the most typical frigates of the early 18th century, on the second deck of fourth-rate ships of the line, and on the upper decks or castles of 80-gun and 120-gun ships of the line. Naval 12-pounders were similar to 12-pound Army guns in the Gribeauval system: the canon lourd de 12 Gribeauval, used as a siege weapon, and the canon de 12 Gribeauval, which was considered a heavy field artillery piece.

Siege artillery (also siege guns or siege cannons) are heavy guns designed to bombard fortifications, cities, and other fixed targets. They are distinct from field artillery and are a class of siege weapon capable of firing heavy cannonballs or shells that required enormous transport and logistical support to operate. They lacked mobility and thus were rarely useful in more mobile warfare situations, generally having been superseded by heavy howitzers (towed and self-propelled artillery), strategic bomber aircraft, surface-to-surface missiles, ballistic missiles, cruise missiles and multiple rocket launchers in modern warfare.