Berm

A berm is a level space, shelf or raised barrier, usually of compacted soil, that separates areas vertically and is often placed partway up a long slope. People build berms as terrace roads, tracks and paths, fortification lines, navigation borders, drainage works and spill containment barriers. The word comes from Middle Dutch and reached English through French. In coastal geography the term has a natural meaning: a berm is a bank or ridge of sand or gravel running parallel to the shoreline and standing a few tens of centimetres high. Waves build it by throwing material beyond the average level of the sea, so it marks the upper limit of ordinary wave action on a beach. The same word therefore covers both engineered earthworks and a small natural beach feature.