Parapet
Parapet , noun
[French, from Italian parapetto, from parare to ward off, guard (Latin parare to prepare, provide) + petto the breast, Latin pectus. See Parry, and Pectoral.]
1.
(Architecture) A low wall, especially one serving to protect the edge of a platform, roof, bridge, or the like.
2.
(Fortification) A wall, rampart, or elevation of earth, for covering soldiers from an enemy's fire; a breastwork. See Illust. of Casemate.