BONNET, in a general sense, denotes a cover for the head, in common use before the introduction of hats. See HAT.
Bonnets are still used in many parts of Scotland. BONNET, in fortification, a small work, consisting of two faces, having only a parapet with two rows of palisadoes, of about ten or twelve 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 palisadoes on each side.