n. [ OE. lof, prob. a sort of timber by which the course of a ship was directed, perh. a sort of paddle; cf. D. loef luff, loeven to luff. The word is perh. akin to E. glove. Cf. Aloof. ] (Naut.) (a) The side of a ship toward the wind. (b) The act of sailing a ship close to the wind. (c) The roundest part of a ship's bow. (d) The forward or weather leech of a sail, especially of the jib, spanker, and other fore-and-aft sails. [ 1913 Webster ]

Luff tackle, a purchase composed of a double and single block and fall, used for various purposes. Totten. --
Luff upon luff, a luff tackle attached to the fall of another luff tackle. R. H. Dana, Jr. [ 1913 Webster ]

v. i. [ imp. & p. p. Luffed p. pr. & vb. n. Luffing. ] 1. (Naut.) To turn the head of a vessel toward the wind; to sail nearer the wind; to turn the tiller so as to make the vessel sail nearer the wind. [ 1913 Webster ]

2. (Naut.) To flutter or shake from being aligned close to the direction of the wind; -- said of a sail. [ PJC ]

To luff round, or
To luff alee, to make the extreme of this movement, for the purpose of throwing the ship's head into the wind. [ 1913 Webster ]

n. (Arch.) See Louver. [ 1913 Webster ]