a large sailing ship with three or four masts and a high forecastle and stern, developed in the 15th and 16th cent., and used as both a warship and a trader
See galleon in American Heritage Dictionary 4
(gălˈē-ən, gălˈyən)
noun
A large three-masted sailing ship with a square rig and usually two or more decks, used from the 15th to the 17th century especially by Spain as a merchant ship or warship.