The Collaborative International Dictionary of English v.0.48:

Bowline \Bow"line\, n. [Cf. D. boelijn, Icel. b["o]gl["i]na?,
   Dan. bovline; properly the line attached to the shoulder or
   side of the sail. See Bow (of a ship), and Line.] (Naut.)
   A rope fastened near the middle of the leech or perpendicular
   edge of the square sails, by subordinate ropes, called
   bridles, and used to keep the weather edge of the sail tight
   forward, when the ship is closehauled.
   [1913 Webster]

   Bowline bridles, the ropes by which the bowline is fastened
      to the leech of the sail.

   Bowline knot. See Illust. under Knot.

   On a bowline, close-hauled or sailing close to the wind; --
      said of a ship.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bowline
    n 1: a loop knot that neither slips nor jams [syn: bowline,
         bowline knot]