Sail: piece of canvas that catches the wind to propel a boat.
Luff: the longest side of a triangular sail.
Batten: long, thin piece of wood that supports the sail.
Peak: angle of sail.
Tack: point of attachment of a sail closets to the bottom and into the wind.
Foot: edge of a sail.
Bolt rope: cord protecting the edges of a sail.
Peak: point of attachment of a sail closest to the top and into the wind.