The Collaborative International Dictionary of English v.0.48:

Ianthina \I*an"thi*na\, n.; pl. L. Ianthin[ae], E.
   Ianthinas. [NL., fr. L. ianthinus violet-blue, Gr. ?; ?
   violet + ? flower.] (Zool.)
   Any gastropod of the genus Ianthina, of which various
   species are found living in mid ocean; -- called also purple
   shell, and violet snail. [Written also janthina.]
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   Note: It floats at the surface by means of a raft, which it
         constructs by forming and uniting together air bubbles
         of hardened mucus. The Tyrian purple of the ancients
         was obtained in part from mollusks of this genus.
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The Collaborative International Dictionary of English v.0.48:

Purple \Pur"ple\, a.
   1. Exhibiting or possessing the color called purple, much
      esteemed for its richness and beauty; of a deep red, or
      red and blue color; as, a purple robe.
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   2. Imperial; regal; -- so called from the color having been
      an emblem of imperial authority.
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            Hide in the dust thy purple pride.    --Shelley.
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   3. Blood-red; bloody.
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            May such purple tears be alway shed.  --Shak.
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            I view a field of blood,
            And Tiber rolling with a purple blood. --Dryden.
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   Purple bird (Zool.), the European purple gallinule. See
      under Gallinule.

   Purple copper ore. (Min.) See Bornite.

   Purple grackle (Zool.), the crow blackbird. See under
      Crow.

   Purple martin. See under Martin.

   Purple sandpiper. See under Sandpiper.

   Purple shell. See Ianthina.
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