luff

plural luffs

1. nauticalThe vertical edge of a sail that is closest to the direction of the wind.

   By easing the halyard, the luff of the sail was made to sag to leeward.

   1 more example

   "The man at the helm was watching the luff of the sail and whistling away gently to himself."

   1883, Robert Louis Stevenson, Treasure Island

2. nauticalThe act of sailing a ship close to the wind.
3. nauticalThe roundest part of a ship's bow.
4. nauticalThe forward or weather leech of a sail, especially of the jib, spanker, and other fore-and-aft sails.

present singular third person luffs · participle present luffing · participle past luffed · past luffed

1. intransitivenauticalTo shake due to being trimmed improperly.

   I thought how my life is like a little boat and I must hold the tiller steady against the buffeting of wind and waves, and how sometimes, like this morning, I lose my hold somehow and the sail luffs helplessly and the little vessel wallows, turning this way and that in the swell.

   1993, John Banville, Ghosts

2. intransitivenauticalTo bring the ship's head up closer to the wind. (Alternatively luff up)

   "Helm there! Luff, luff a point! So; steady, man, steady!"

   1851, Herman Melville, Moby Dick

3. transitivenauticalto let out (a sail) so that it luffs.
4. engineeringTo alter the vertical angle of the jib of a crane so as to bring it level with the load.

   The tower is mounted on a slewing platform, which also carries the power plant and the counterweights, while the jib is supported and luffed by fixed pendant ropes.

   1999, Howard I. Shapiro, Jay P. Shapiro, Lawrence K. Shapiro, Cranes and Derricks, →ISBN, page 95

plural Luffs

1. A surname.