bulwark

nouns

an embankment built around a space for defensive purposes

"they stormed the ramparts of the city"; "they blew the trumpet and the walls came tumbling down"

bulwark, rampart, wall

a fencelike structure around a deck (usually plural)

bulwark

is a part of

a vessel that carries passengers or freight

is a type of (narrower)

a structure or object that impedes free movement

a protective structure of stone or concrete; extends from shore into the water to prevent a beach from washing away

breakwater, bulwark, groin, groyne, jetty, mole, seawall

defend with a bulwark

bulwark

is a type of (narrower)

be on the defensive; act against an attack