in a ship, the borders or edges of a sail, which are either sloping or perpendicular.

The leeches of all sails, the tops and bottoms of which are parallel to the deck, or at right angles to the mast, are denominated from the ship's side, and the sail to which they belong; as the starboard leech of the main-sail, the lee leech of the fore-top-sail, and so on. But the sails which are fixed obliquely on the masts have their leeches named from their situation with respect to the ship's length; as the fore-leech of the mizen, the after-leech of the jib or fore-stay sail, and the like.

Leech-Lines, certain ropes fastened to the middle of the leeches of the main-sail and fore-sail, and communicating with blocks under the opposite sides of the top, whence they pass downwards to the deck, and serve to truss up those sails to the yard as occasion requires.

Leech-Rope, a name given to that part of the bolt-rope to which the border or skirt of a sail is sewed. In all sails, the opposite leeches of which are of the same length, it is terminated above the earing, and below the clue.