A four-master is a type of sailboat or ship that has four masts. There are also several synonyms for this term that can be used in different contexts, such as quadrimasted, four-masted ship, or four-masted vessel. In some cases, the term "barque" may be used as well, as this refers to a sailing vessel with at least three masts, the forward mast of which is a foremast. Other terms that can be used as synonyms for a four-master include a brigantine or brig, which describes a vessel with two masts, both of which are square-rigged. Ultimately, the term used to describe a four-master will depend on its specific design and construction.