A bombard is a type of medieval cannon or mortar, used chiefly in sieges for throwing heavy stone balls. The modern term bombardment derives from this.
A notable example of a bombard is the large Mons Meg weapon, built around 1449 and used by King James II of Scotland. Mons Meg was capable of firing 180 kg (396 lb) shots and was one of the largest bombards ever built. It is now housed on public display at Edinburgh Castle.
This weapon was usually used during sieges to hurl various forms of missile into enemy fortifications,such as stone or metal ball and burning materials, or a weighted cloth soaked in quicklime or greek fire.
In the popular PC game Medieval II Total War certain factions are granted access to bombards to use on their enemies. However, the largest in the game, the "Monster Bombard" which is only available to the Turk and Timurid factions is much larger than Mons Meg weapon. In the game, it is mentioned that the Monster Bombard can fire shots well over half a ton. The barrel is supported by large chains and held on a large wooden frame. However, the crew is able to move it as quickly as a ballista, the smallest siege weapon. The player is never shown how you reload the massive gun due to the obvious near impossibility but is told it takes an "eternity". This is a huge exaggeration of Mons Meg but put in the game to add challenge and uniqueness by a large degree.
The name derives through medieval Latin and French forms from a Greek word expressing the making of a humming noise.
Original text from the 1911 Encyclopædia Britannica
Eventually however, bombards were superseded by weapons utilizing smaller calibre iron projectiles using more powerful gunpowder.