The Collaborative International Dictionary of English v.0.48:

Preference \Pref"er*ence\, n. [Cf. F. pr['e]f['e]rence.]
   1. The act of Preferring, or the state of being preferred;
      the setting of one thing before another; precedence;
      higher estimation; predilection; choice; also, the power
      or opportunity of choosing; as, to give him his
      preference.
      [1913 Webster]

            Leave the critics on either side to contend about
            the preference due to this or that sort of poetry.
                                                  --Dryden.
      [1913 Webster]

            Knowledge of things alone gives a value to our
            reasonings, and preference of one man's knowledge
            over another's.                       --Locke.
      [1913 Webster]

   2. That which is preferred; the object of choice or superior
      favor; as, which is your preference?
      [1913 Webster]

WordNet (r) 3.0 (2006):

preference
    n 1: a strong liking; "my own preference is for good
         literature"; "the Irish have a penchant for blarney" [syn:
         preference, penchant, predilection, taste]
    2: a predisposition in favor of something; "a predilection for
       expensive cars"; "his sexual preferences"; "showed a Marxist
       orientation" [syn: predilection, preference,
       orientation]
    3: the right or chance to choose; "given my druthers, I'd eat
       cake" [syn: preference, druthers]
    4: grant of favor or advantage to one over another (especially
       to a country or countries in matters of international trade,
       such as levying duties)

The Devil's Dictionary (1881-1906):

PREFERENCE, n.  A sentiment, or frame of mind, induced by the
erroneous belief that one thing is better than another.
    An ancient philosopher, expounding his conviction that life is no
better than death, was asked by a disciple why, then, he did not die.
"Because," he replied, "death is no better than life."
    It is longer.