Galleass

noun

1. A large, fast, heavily armed three-masted Mediterranean galley of the 1500s and 1600s.
2. A large galley formerly used in the Mediterranean, carrying generally three masts and perhaps twenty guns, and having castellated structures fore and aft, and seats amidships for the rowers, who were galley-slaves, and numbered sometimes more than three hundred, there being as many as thirty-two oars on a side, each worked by several men.
3. A large galley, having some features of the galleon, as broadside guns; esp., such a vessel used by the southern nations of Europe in the 16th and 17th centuries. See galleon, and galley.
4. A type of rowable vessel of the 16th and 17th centuries, similar to a galley but larger, and normally equipped with sails.