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