Agger

A technical term of ancient Roman roadwork for an earthen mound, embankment, or rampart of a camp, formed by the earth dug out of a ditch. Most Roman roads were built on a slightly raised causeway, mainly to provide drainage. This bank of earth was used for protection from flooding, as the foundation for a road, or for warfare purposes. Agger is also a general term for a mound formed by a dike, quay, roadwork, or earthwork. An agger can often be traced even if the surfacing material has been covered or laid bare.

A Latin military term meaning a rampart, earthwork or embankment. The term is applied in a broad way and is used, for instance, for the artificial earthworks erected to support battering engines and for the slightly raised causeway that formed the basis of most Roman roads.