Second mast from the bow of a ship, barque or schooner.
the chief mast of a sailing vessel with two or more masts
usually, the principal and the heaviest mast of two or more. In yawls and ketches, the forward mast is the mainmast; in schooners and vessels with more than two masts, it is the second mast from forward.
(or Main) - The tallest mast on a ship.
Spars , Parts Mainsail Sails , Rigging
Second mast aft from the bow.
the largest, and main, mast.
Aboard the three-masted Concordia, the middle of the three
The tallest mast on the ship. cf foremast and mizzenmast. (See rigging illustration.)
the tallest mast of the ship; on a schooner, the mast furthest aft.