Nouns

(n)rampart, bulwark, wallan 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”
(n)bulwarka fencelike structure around a deck
(n)breakwater, groin, groyne, mole1, bulwark, seawall, jettya protective structure of stone or concrete; extends from shore into the water to prevent a beach from washing away

Verbs

(v)bulwarkdefend with a bulwark