Luff
Origin
Collins English Dictionary states that this word is ultimately derived from Middle Dutch loef.
Dictionary.com
Ellert Ekwall's Shakspere's Vocabulary: its etymological elements (1903) related this verb and loof instead to the East Frisian
verb lofen, lufen, which would make it cognate to the French term lover.
Full definition of luff
Noun
luff
(plural luffs)- (nautical) The 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.
- (nautical) The act of sailing a ship close to the wind.
- (nautical) The roundest part of a ship's bow.
- (nautical) The forward or weather leech of a sail, especially of the jib, spanker, and other fore-and-aft sails.
Verb
- (nautical, of a sail, intransitive) To shake due to being trimmed improperly.
- (nautical, of a boat, intransitive) To alter course to windward so that the sails luff. (Alternatively luff up)
- (nautical, transitive) to let out sail so that it luffs.
- (mechanical) To alter the vertical angle of the jib of a crane so as to bring it level with the load.
- 1999, Howard I. Shapiro, Jay P. Shapiro, Lawrence K. Shapiro, Cranes and Derricks, 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.