Caponier

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...
Found on http://en.wikipedia.org/wiki/Caponier

caponier

covered passage across a moat or ditch
Found on http://phrontistery.info/c.html

Caponier

covered passage within a ditch
Found on https://www.encyclo.co.uk/local/20402

Caponier

covered passage within a ditch
Found on http://www.encyclo.co.uk/local/22129
No exact match found