Tack

To go about; a vessel is on the starboard tack when the wind blows on the starboard side, and on the port tack when the wind blows on the port side; the tackle by which the clew of a course is hauled forward and down; the tack line or tack pennant of a fore-and-aft or gaff topsail is the rope that keeps down the tack of the sail, or the lower forward corner; the rope that keeps down the lower outer corner of a studding sail.