What is the meaning of Jetty?

A structure of wood or stone extended into the sea to influence the current or tide, or to protect a harbor or beach.

A dock or wharf extending from the shore; a pier.

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

To jut out; to project.

Made of jet, or like jet in color.

Source: wiktionary.org