A fore-and-aft sail, bent to a gaff, and hoisted on a lower mast or on a small mast, called the trysail mast, close abaft a lower mast; -- used chiefly as a storm sail. Called also spencer.
Also called storm trysail. A very strong sail used in stormy weather. It is loose footed, being attached to the mast but not the boom. This helps prevent boarding waves from damaging the sail or the rigging.