The Collaborative International Dictionary of English v.0.48:

Stigma \Stig"ma\, n.; pl. E. Stigmas, L. Stigmata. [L., a
   mark, a brand, from Gr. ?, ?, the prick or mark of a pointed
   instrument, a spot, mark, from ? to prick, to brand. See
   Stick, v. t.]
   1. A mark made with a burning iron; a brand.
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   2. Any mark of infamy or disgrace; sign of moral blemish;
      stain or reproach caused by dishonorable conduct;
      reproachful characterization.
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            The blackest stigma that can be fastened upon him.
                                                  --Bp. Hall.
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            All such slaughters were from thence called
            Bartelmies, simply in a perpetual stigma of that
            butchery.                             --Sir G. Buck.
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   3. (Bot.) That part of a pistil which has no epidermis, and
      is fitted to receive the pollen. It is usually the
      terminal portion, and is commonly somewhat glutinous or
      viscid. See Illust. of Stamen and of Flower.
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   4. (Anat.) A small spot, mark, scar, or a minute hole; --
      applied especially to a spot on the outer surface of a
      Graafian follicle, and to spots of intercellular substance
      in scaly epithelium, or to minute holes in such spots.
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   5. (Pathol.) A red speck upon the skin, produced either by
      the extravasation of blood, as in the bloody sweat
      characteristic of certain varieties of religious ecstasy,
      or by capillary congestion, as in the case of drunkards.
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   6. (Zool.)
      (a) One of the external openings of the tracheae of
          insects, myriapods, and other arthropods; a spiracle.
      (b) One of the apertures of the pulmonary sacs of
          arachnids. See Illust. of Scorpion.
      (c) One of the apertures of the gill of an ascidian, and
          of Amphioxus.
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   7. (Geom.) A point so connected by any law whatever with
      another point, called an index, that as the index moves in
      any manner in a plane the first point or stigma moves in a
      determinate way in the same plane.
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   8. pl. (R. C. Ch.) Marks believed to have been supernaturally
      impressed upon the bodies of certain persons in imitation
      of the wounds on the crucified body of Christ. See def. 5,
      above.
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