A long artificial mound of stone or earth; built to hold back water or to support a road or as protection WordNet 3.0 & Open English WordNet

A road, railway line, or canal is normally raised onto an embankment made of compacted soil to avoid a change in level required by the terrain, the alternatives being either to have an unacceptable change in level or detour to follow a contour. Wikipedia

A raised bank to carry a road, railway, or canal across a low-lying or wet area Wikipedia Disambiguation

Wall or bank to carry a road or rail over low ground or water's edge Wikidata

A long mound of earth, stone, or similar material, usually built for purposes such as to hold back or store water, for protection from weather or enemies, or to support a road or railway. Wiktionary

Artificial mound of earth and stone. Wiktionary (translation)