Source : Webster's Revised Unabridged Dictionary (1913)

Lief \Lief\ (l[=e]f), n.
   Same as {Lif}.

Lief \Lief\ (l[=e]f), a. [Written also {lieve}.] [OE. leef, lef,
   leof, AS. le['o]f; akin to OS. liof, OFries. liaf, D. lief,
   G. lieb, OHG. liob, Icel. lj[=u]fr, Sw. ljuf, Goth. liubs,
   and E. love. [root]124. See {Love}, and cf. {Believe},
   {Leave}, n., {Furlough}, {Libidinous}.]
   1. Dear; beloved. [Obs., except in poetry.] ``My liefe
      mother.'' --Chaucer. ``My liefest liege.'' --Shak.

            As thou art lief and dear.            --Tennyson.

   2.

   Note: (Used with a form of the verb to be, and the dative of
         the personal pronoun.) Pleasing; agreeable; acceptable;
         preferable. [Obs.] See {Lief}, adv., and Had as lief,
         under {Had}.

               Full lief me were this counsel for to hide.
                                                  --Chaucer.

               Death me liefer were than such despite.
                                                  --Spenser.

   3. Willing; disposed. [Obs.]

            I am not lief to gab.                 --Chaucer.

            He up arose, however lief or loth.    --Spenser.

Lief \Lief\, n.
   A dear one; a sweetheart. [Obs.] --Chaucer.

Lief \Lief\, adv.
   Gladly; willingly; freely; -- now used only in the phrases,
   had as lief, and would as lief; as, I had, or would, as lief
   go as not.

         All women liefest would Be sovereign of man's love.
                                                  --Gower.

         I had as lief the town crier spoke my lines. --Shak.

         Far liefer by his dear hand had I die.   --Tennyson.

   Note: The comparative liefer with had or would, and followed
         by the infinitive, either with or without the sign to,
         signifies prefer, choose as preferable, would or had
         rather. In the 16th century rather was substituted for
         liefer in such constructions in literary English, and
         has continued to be generally so used. See {Had as
         lief}, {Had rather}, etc., under {Had}.

Source : WordNet®

lief
     adj : (`lief' is archaic) very willing; "was lief to go"; "glad to
           help" [syn: {glad}, {lief(p)}]
     adv : in a willing manner; "this was gladly agreed to"; "I would
           fain do it" [syn: {gladly}, {fain}]