The Collaborative International Dictionary of English v.0.48:

Crystalline \Crys"tal*line\ (kr?s"tal-l?n or -l?n; 277), a. [L.
   crystallinus, from Gr. ????: cf. F. cristallin. See
   Crystal.]
   1. Consisting, or made, of crystal.
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            Mount, eagle, to my palace crystalline. --Shak.
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   2. Formed by crystallization; like crystal in texture.
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            Their crystalline structure.          --Whewell.
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   3. Imperfectly crystallized; as, granite is only crystalline,
      while quartz crystal is perfectly crystallized.
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   4. Fig.: Resembling crystal; pure; transparent; pellucid.
      "The crystalline sky." --Milton.
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   Crystalline heavens, or Crystalline spheres, in the
      Ptolemaic system of astronomy, two transparent spheres
      imagined to exist between the region of the fixed stars
      and the primum mobile (or outer circle of the heavens,
      which by its motion was supposed to carry round all those
      within it), in order to explain certain movements of the
      heavenly bodies.

   Crystalline lens (Anat.), the capsular lenslike body in the
      eye, serving to focus the rays of light. It consists of
      rodlike cells derived from the external embryonic
      epithelium.
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The Collaborative International Dictionary of English v.0.48:

Crystalline \Crys"tal*line\, n.
   1. A crystalline substance.
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   2. See Aniline. [Obs.]
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WordNet (r) 3.0 (2006):

crystalline
    adj 1: consisting of or containing or of the nature of crystals;
           "granite is crystalline" [ant: noncrystalline]
    2: distinctly or sharply outlined; "crystalline sharpness of
       outline"- John Buchan
    3: transmitting light; able to be seen through with clarity;
       "the cold crystalline water of melted snow"; "crystal clear
       skies"; "could see the sand on the bottom of the limpid
       pool"; "lucid air"; "a pellucid brook"; "transparent crystal"
       [syn: crystalline, crystal clear, limpid, lucid,
       pellucid, transparent]

Moby Thesaurus II by Grady Ward, 1.0:

70 Moby Thesaurus words for "crystalline":
   clean-cut, clear, clear as crystal, clear as day, clear-cut,
   coherent, connected, consistent, craggy, crisp, crystal,
   crystal-clear, defined, definite, diaphane, diaphanous, direct,
   distinct, explicit, express, filmy, gauzy, gossamer, gossamery,
   gravelly, gritty, lapideous, light-pervious, limpid, lithoid,
   lithoidal, loud and clear, lucid, luminous, monolithic, nonopaque,
   pebbled, pebbly, peekaboo, pellucid, perspicuous, plain,
   porphyritic, revealing, rock-ribbed, rock-strewn, rock-studded,
   rocklike, rocky, sandy, see-through, sheer, shingled, shingly,
   simple, stonelike, stony, straightforward, thin, trachytic,
   translucent, transparent, transpicuous, unambiguous, unclouded,
   unconfused, unequivocal, univocal, unmistakable, well-defined