Dredge (up) is a term used to describe the process of unearthing or uncovering something from the ground, usually with a RAKE. It can also refer to the act of raking up material from the bottom of a body of water. Dredging is often used in construction and mining operations, as well as for cleaning up rivers and lakes. In addition, dredging can be used to remove sediment from the ocean floor, which can help protect coastal areas from erosion.