A caponier is a type of fortification structure. The word originates from the French word caponnière. The fire coming from the feature (e.g. muskets, machine-guns, case-shot etc.) sweeps along the bottom of the attendant ditch that constricts the movement of storming infantrymen to an enfilade alignment of greatest exposure and so prevents the en...
covered passage across a moat or ditch
covered passage within a ditch
covered passage within a ditch