The Collaborative International Dictionary of English v.0.48:

Specialty \Spe"cial*ty\, n.; pl. Specialties. [F.
   sp['e]cialit['e]. Cf. Speciality.]
   1. Particularity.
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            Specialty of rule hath been neglected. --Shak.
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   2. A particular or peculiar case. [Obs.]
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   3. (Law) A contract or obligation under seal; a contract by
      deed; a writing, under seal, given as security for a debt
      particularly specified. --Chitty. --Bouvier. --Wharton
      (Law Dict.).
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            Let specialties be therefore drawn between us.
                                                  --Shak.
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   4. That for which a person is distinguished, in which he is
      specially versed, or which he makes an object of special
      attention; a speciality.
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            Men of boundless knowledge, like Humbold, must have
            had once their specialty, their pet subject. --C.
                                                  Kingsley.
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WordNet (r) 3.0 (2006):

specialty
    n 1: an asset of special worth or utility; "cooking is his
         forte" [syn: forte, strong suit, long suit, metier,
         specialty, speciality, strong point, strength]
         [ant: weak point]
    2: a distinguishing trait [syn: peculiarity, specialness,
       specialty, speciality, distinctiveness]
    3: the special line of work you have adopted as your career;
       "his specialization is gastroenterology" [syn:
       specialization, specialisation, specialty,
       speciality, specialism]