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)

Moby Thesaurus II by Grady Ward, 1.0:

129 Moby Thesaurus words for "preference":
   affinity, alternative, alternativity, animus, antecedence,
   antecedency, anteposition, anteriority, aptitude, bag, bent, bias,
   cast, character, choice, choosing, chosen kind, co-optation,
   co-option, constitution, cosset, cup of tea, darling, decision,
   desire, diathesis, discrimination, disposition, dominion, druthers,
   eccentricity, election, elevation, fancy, fascination, favor,
   favorite, favoritism, first choice, fondling, free choice,
   free will, front position, grain, idiosyncrasy, idol, inclination,
   individualism, inequality, interest, involvement, jewel, kidney,
   leaning, liking, make, makeup, matinee idol, mental set, mettle,
   mind, mind-set, minion, mold, mutual affinity, mutual attraction,
   nature, nepotism, one-sidedness, option, parti pris, partiality,
   particular choice, partisanism, partisanship, penchant,
   personal choice, pet, pick, precedence, precedency, preceding,
   precession, precursor, predilection, predisposition,
   preferential treatment, preferment, prefixation, prejudice,
   prelude, preoption, prepossession, priority, proclivity, promotion,
   propensity, prothesis, selection, set, slant, spoiled child, stamp,
   strain, streak, stripe, style, superiority, sympathy, taste,
   temper, temperament, tendency, the lead, the pick, thing,
   top priority, turn, turn of mind, twist, type, undetachment,
   undispassionateness, unneutrality, upgrading, urgency, volition,
   warp, will



Bouvier's Law Dictionary, Revised 6th Ed (1856):

PREFERENCE. The paying or securing to one or more of his creditors, by an
insolvent debtor, the whole or a part of their claim, to the exclusion of
the rest. By preference is also meant the right which a creditor has
acquired over others to be paid first out of the assets of his debtor, as,
when a creditor has obtained a judgment against his debtor which binds the
latter's land, he has a preference.
     2. Voluntary preferences are forbidden by the insolvent laws of some of
the states, and are void, when made in a general assignment for the benefit
of creditors. Vide Insolvent; Priority.



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.