*terreplein*

n. [ F., fr. L. terra earth + planus even, level, plain. ] 1. (Fort.) The top, platform, or horizontal surface, of a rampart, on which the cannon are placed. See Illust. of Casemate. [ 1913 Webster ]

2. (Civ. Engin.) An embankment of earth with a broad level top, which is sometimes excavated to form a continuation of an elevated canal across a valley. [ Webster 1913 Suppl. ]