\Luff\, 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.
{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.

\Luff\, v. i. [imp. & p. p. {Luffed}; p. pr. & vb. n.
{Luffing}.] (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.
{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.