Jet″ty, n.; pl.Jetties (#). [F. jetée a pier, a jetty, a causeway. See Jet a shooting forth, and cf. Jutty.]
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.