Demi-cannon

Type of muzzle-loading cannon

The demi-cannon was a medium-sized cannon, similar to but slightly larger than a culverin and smaller than a regular 42 pounds (19 kg) cannon, developed in the early 17th century. A full cannon fired a 42-pound shot, but these were discontinued in the 18th century as they were seen as too unwieldy. The lower tiers of 18th century English warships were usually equipped with demi-cannons.

This keyword could refer to multiple things. Here are some suggestions: