Buttressing, Citadel, Cofferdam, Contraceptive, Copyright, Cover, Curtain, Cushion, Dam, Dashboard, Defend, Ditch, Dodger, Drawbridge, Earthwork, Embankment, Enclosure, Entanglement, Escarp, Escarpment, Fence, Fend, Fender, Fieldwork, Fort, Fortification, Fortress, Fuse, Gate, Goggles, Governor, Groin, Guard, Handrail, Helmet, Insulation, Interlock, Jam, Jetty, Lifeline, Logjam, Loophole, Mask, Moat, Mole, Mound, Mudguard, Outwork, Pad, Padding, Palisade, Palladium, Parapet, Patent, Pier, Pilot, Portcullis, Preventive, Prophylactic, Protect, Rampart, Abutment, Aegis, Bank, Bar, Barrage, Barricade, Barrier, Bastion, Battlement, Beam, Boom, Breakwater, Buffer, Bulkhead, Bumper, Buttress, Redoubt, Roadblock, Safeguard, Safety, Scarp, Screen, Secure, Shelter, Shield, Shoulder, Stockade, Stronghold, Umbrella, Wall, Weir, Windscreen, Work