1. (a.) Made of jet, or like jet in color.

2. (n.) A part of a building that jets or projects beyond the rest, and overhangs the wall below.

3. (n.) A wharf or pier extending from the shore.

4. (n.) 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.

5. (v. i.) To jut out; to project.

abutment anchorage anchorage ground arc-boutant arch dam backstop bamboo curtain bank bar barrage barrier basin beam bear-trap dam beaver dam berth black boom breakwater breastwork brick wall buffer bulkhead bulwark buttress buttress pier buttressing cofferdam dam defense dike ditch dock dockage dockyard dry dock earthwork ebon ebony embankment fence flying buttress gate gravity dam groin hanging buttress harbor harborage haven hydraulic-fill dam inky iron curtain jam jet jutty landing landing place landing stage leaping weir levee logjam marina milldam moat mole moorings mound parapet pier pier buttress pitch-black pitch-dark port portcullis protected anchorage quay rampart raven retaining wall road roadblock roads roadstead rock-fill dam sable seaport seawall shipyard shoulder shutter dam slip stone wall wall weir wharf wicket dam work