BONNET, in Fortification, a small work consisting of two faces, having only a parapet with two rows of palisades, of about 10 or 12 feet distance; it is generally raised before the salient angle of the counterscarp, and has a communication with the covered way, by a trench cut through the glacis, and palisades on each side.
BONNET à Pretre, or Priest's Bonnet, in Fortification, is an out-work, having at the head three salient angles, and two inwards. It differs from the double tenaille only in this, that its sides, instead of being parallel, are like the queue d'aronde, or swallow's tail, that is, narrowing, or drawing close at the gorge, and opening at the head.