Artificial basins excavated and often built up with masonry or another material, and often fitted with flood-gates, into which boats or ships are received for purposes of landing, loading and unloading, or for repair. The earliest known docks date to ca. 2500 BCE in Egypt. The plural term is often used to refer to a single such artificial basin. When such spaces are unoccupied and are alongside a landing place, use "berths (waterfront spaces)"; use "slips (waterfront spaces)" when such water spaces are unoccupied and set between adjacent piers or perpendicular to landing places. Use "dockyards" for the group of landing places in ports or for port facilities as a whole. For the structures that surround a dock, excluding the space occupied by water, prefer "piers (marine landings)" or "wharves." For structures used for docking for various purposes, use "dry docks," "wet docks," or "floating docks." Distinguished from the structures, "docks (general waterside structures)," which in casual, modern usage may refer to any waterside structure supporting people or their activities.

Source: Art and Architecture Thesaurus
http://vocab.getty.edu/page/aat/300120801