Clews - The lower corners of a square sail
Head - The upper edge of a square sail.
Leech - The vertical edge of a square sail.
Yard � The spar to which the head of a square sail is tied.
Boom - The spar to which the foot of a fore-and-aft sail is tied.
Clew - The aft-lower corner of a fore-and-aft sail.
Gaff - The spar to which the head of a fore-and-aft sail is tied.
Head - The top edge of a four sided sail or the top corner of a triangular sail.
Leech - The aft edge of a fore-and-aft sail.
Luff - The forward edge of a fore-and-aft sail.
Tack - The forward-lower corner of a fore-and-aft sail.