The Collaborative International Dictionary of English v.0.48:

Odds \Odds\ ([o^]dz), n. sing. & pl. [See Odd, a.]
   1. Difference in favor of one and against another; excess of
      one of two things or numbers over the other; inequality;
      advantage; superiority; hence, excess of chances;
      probability. The odds are often expressed by a ratio; as,
      the odds are three to one that he will win, i. e. he will
      win three times out of four "Preeminent by so much odds."
      --Milton. "The fearful odds of that unequal fray."
      --Trench.
      [1913 Webster]

            The odds
            Is that we scarce are men and you are gods. --Shak.
      [1913 Webster]

            There appeared, at least, four to one odds against
            them.                                 --Swift.
      [1913 Webster]

            All the odds between them has been the different
            scope . . . given to their understandings to range
            in.                                   --Locke.
      [1913 Webster]

            Judging is balancing an account and determining on
            which side the odds lie.              --Locke.
      [1913 Webster]

   2. Quarrel; dispute; debate; strife; -- chiefly in the phrase
      at odds.
      [1913 Webster]

            Set them into confounding odds.       --Shak.
      [1913 Webster]

            I can not speak
            Any beginning to this peevish odds.   --Shak.
      [1913 Webster]

   At odds, in dispute; at variance. "These squires at odds
      did fall." --Spenser. "He flashes into one gross crime or
      other, that sets us all at odds." --Shak.

   It is odds, it is probable; same as odds are, but no
      longer used. [Obs.] --Jer. Taylor.

   odds are it is probable; as, odds are he will win the gold
      medal.

   Odds and ends, that which is left; remnants; fragments;
      refuse; scraps; miscellaneous articles. "My brain is
      filled . . . with all kinds of odds and ends." --W.
      Irving.

   slim odds low odds; poor chances; as, there are slim odds
      he will win any medal.
      [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

at odds
    adj 1: in disagreement; "the figures are at odds with our
           findings"; "contradictory attributes of unjust justice
           and loving vindictiveness"- John Morley [syn: at
           odds(p), conflicting, contradictory, self-
           contradictory]

Moby Thesaurus II by Grady Ward, 1.0:

135 Moby Thesaurus words for "at odds":
   against the grain, against the tide, against the wind, alienated,
   antagonistic, antiestablishment, antipathetic, assorted,
   at cross-purposes, at daggers, at daggers drawn, at enmity,
   at feud, at issue, at loggerheads, at odds with, at outs,
   at square, at strife, at variance, at variance with, at war,
   at war with, athwart, averse, breakaway, clashing, contra,
   contradictory, contrariwise, contrary, contrasted, contrasting,
   counter, counter-culture, cranky, cross, cursory, departing,
   deviating, deviative, different, differentiated, differing,
   disaccordant, disagreeable, disagreeing, discordant, discrepant,
   discrete, discriminated, disharmonious, disinclined, disjoined,
   disobedient, disparate, disproportionate, dissentient, dissenting,
   dissident, dissimilar, dissonant, distinct, distinguished,
   divergent, diverging, divers, diverse, diversified,
   eyeball-to-eyeball, forced, fractious, grating, heterogeneous,
   hostile, immiscible, in confrontation, in disagreement,
   in hostile array, in opposition, inaccordant, incompatible,
   incongruous, inconsistent, inconsonant, indisposed, indocile,
   inharmonious, involuntary, irreconcilable, jangling, jarring, many,
   motley, multifarious, mutinous, negative, nonconforming,
   on the outs, opposed, opposing, out of accord, out of whack,
   perfunctory, poles apart, poles asunder, recalcitrant, recusant,
   refractory, repugnant, resistant, sectarian, sectary, separate,
   separated, several, sulky, sullen, unconformable, uncongenial,
   unconsenting, underground, unequal, unharmonious, unlike,
   unwilling, up in arms, variant, varied, variegated, various,
   varying, widely apart, with crossed bayonets, worlds apart