parapet

noun

1. Fortification.
   1. a defensive wall or elevation, as of earth or stone, in a fortification.
   2. an elevation raised above the main wall or rampart of a permanent fortification.
2. any low protective wall or barrier at the edge of a balcony, roof, bridge, or the like.

noun

1. a low wall or railing along the edge of a balcony, roof, etc
2. Also called: breastwork a rampart, mound of sandbags, bank, etc, in front of a trench, giving protection from fire from the front

n.1580s, from Middle French parapet “breastwork” (16c.), or directly from Italian parapetto, from para- “defense” (see para- (2)) + petto “breast,” from Latin pectus (see pectoral (adj.)).