1. Plural of caponier: a covered passage or gallery in a fortification that allows defenders to move safely between different parts of a fort or to fire across a ditch or moat.
Usage: military/fortification term; also spelled 'caponnière' in French contexts

Examples

• The fort's caponiers provided protected routes for soldiers to reinforce the walls.
• Engineers designed caponiers to allow defenders to rake the ditch with crossfire.
• The caponiers connected the main bastion to the outer works.
• During the siege, troops moved through the caponiers to avoid enemy fire.