Jet·ty, n.; pl. Jetties
1. Arch. A part of a building that jets or projects beyond the rest, and overhangs the wall below.
2. A wharf or pier extending from the shore.
3. Hydraul. Engin. A structure of wood or stone extended into the sea to influence the current or tide, or to protect a harbor; a mole; as, the Eads system of jetties at the mouth of the Mississippi River.
Jetty head Naut., a projecting part at the end of a wharf; the front of a wharf whose side forms one of the cheeks of a dock.