Bastions surrounded only with a rampart and parapet, having the space within unoccupied where the ground is so low that no retrenchment can be made in the center in the event of the rampart being taken.
Related term(s): Bastion; Rampart; Parapet; Bastions, Solid; Bastion, Regular; Bastion, Cut
Category: Castles and Fortifications
Source information: Wilhelm, Thomas. A Military Dictionary and Gazetteer. Philadelphia: L.R. Hamersly & Co., 1881. 49.