The Collaborative International Dictionary of English v.0.48:

Unfair \Un*fair"\, a. [AS. unf[ae]ger unlovely. See Un- not,
   and Fair, a.]
   Not fair; not honest; not impartial; disingenuous; using or
   involving trick or artifice; dishonest; unjust; unequal.
   [1913 Webster]

         You come, like an unfair merchant, to charge me with
         being in your debt.                      --Swift.
   [1913 Webster] -- Un*fair"ly, adv. -- Un*fair"ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

unfairness
    n 1: partiality that is not fair or equitable [ant: candor,
         candour, fair-mindedness, fairness]
    2: injustice by virtue of not conforming with rules or standards
       [syn: unfairness, inequity] [ant: equity, fairness]
    3: an unjust act [syn: injustice, unfairness, iniquity,
       shabbiness]