The Collaborative International Dictionary of English v.0.48:

Singularity \Sin`gu*lar"i*ty\
   (s[i^][ng]`g[-u]*l[a^]r"[i^]*t[y^]), n.; pl. Singularities
   (s[i^][ng]`g[-u]*l[a^]r"[i^]*t[i^]z). [L. singularitas: cf.
   F. singularit['e].]
   1. The quality or state of being singular; some character or
      quality of a thing by which it is distinguished from all,
      or from most, others; peculiarity.
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            Pliny addeth this singularity to that soil, that the
            second year the very falling down of the seeds
            yieldeth corn.                        --Sir. W.
                                                  Raleigh.
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            I took notice of this little figure for the
            singularity of the instrument.        --Addison.
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   2. Anything singular, rare, or curious.
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            Your gallery
            Have we passed through, not without much content
            In many singularities.                --Shak.
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   3. Possession of a particular or exclusive privilege,
      prerogative, or distinction.
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            No bishop of Rome ever took upon him this name of
            singularity [universal bishop].       --Hooker.
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            Catholicism . . . must be understood in opposition
            to the legal singularity of the Jewish nation. --Bp.
                                                  Pearson.
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   4. Celibacy. [Obs.] --Jer. Taylor.
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WordNet (r) 3.0 (2006):

singularity
    n 1: the quality of being one of a kind; "that singularity
         distinguished him from all his companions" [syn:
         singularity, uniqueness]
    2: strangeness by virtue of being remarkable or unusual