caponniere

In fortification, a covered lodgment, sunk four or five feet into the ground, encompassed with a parapet, about two feet high, serving to support several planks, laden with earth. It is large enough to contain 15 or 20 soldiers, and is placed in the glacis, at the extremity of the counterscarp, and in dry moats, with embrasures or loop holes, through which the soldiers may fire.