Galleass n. : 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.

Example:
How far could Medieval Ships Travel?

Taxonomy
galleys, oars, the Mediterranean, steering oars, triremes, sails, rowers, vessel, galleass, oarsmen, galley slaves, hulls, design, galleasses, masts, warships, benches, battle.

Defination from the web:
galleass exemplified an intermediate type between the galley and the true man-of-war. ... In the 15th century a type of light galleass, called the frigate, was built in southern European countries to answer the ... Retrieved from "http://en.wikipedia.org/wiki/Galley#Galleass" ...