abatis, advanced work, arch dam, backstop, balistraria, bamboo curtain, bank, banquette, bar, barbed-wire entanglement, barbican, barrage, barricade, barrier, bartizan, bastion, battlement, bear-trap dam, beaver dam, boom, breakwater, breastwork, brick wall, buffer, bulkhead, bulwark, casemate, cheval-de-frise, circumvallation, cofferdam, contravallation, counterscarp, curtain, dam, defense, demibastion, dike, ditch, drawbridge, earthwork, embankment, enclosure, entanglement, escarp, escarpment, fence, fieldwork, fortalice, fortification, gate, glacis, gravity dam, groin, hydraulic-fill dam, iron curtain, jam, jetty, leaping weir, levee, logjam, loophole, lunette, machicolation, mantelet, merlon, milldam, moat, mole, mound, outwork, palisade, parados, portcullis, postern gate, rampart, ravelin, redan, redoubt, roadblock, rock-fill dam, sally port, scarp, sconce, seawall, shutter dam, stockade, stone wall, tackling, tenaille, vallation, vallum, wall, weir, wicket dam, work