vallation

val·la·tion

V0013300 (vă-lā′shən)n.1. An earthwork wall used for military defense; a rampart.2. The process of planning or erecting earth fortifications.
[Late Latin vallātiō, vallātiōn-, from Latin vallātus, past participle of vallāre, to surround with a rampart, from vallum, rampart, from vallus, stake.]
val′la·to′ry (văl′ə-tôr′ē) adj.

vallation

(vəˈleɪʃən) n1. (Fortifications) the act or process of building fortifications2. (Fortifications) a wall or rampart[C17: from Late Latin vallātiō, from vallum rampart]