The Collaborative International Dictionary of English v.0.48:

Sclerotic \Scle*rot"ic\, a. [Gr. sklhro`s hard: cf. F.
   scl['e]rotique.]
   1. Hard; firm; indurated; -- applied especially in anatomy to
      the firm outer coat of the eyeball, which is often
      cartilaginous and sometimes bony.
      [1913 Webster]

   2. (Anat.) Of or pertaining to the sclerotic coat of the eye;
      sclerotical.
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   3. (Med.) Affected with sclerosis; sclerosed.
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   Sclerotic parenchyma (Bot.), sclerenchyma. By some writers
      a distinction is made, sclerotic parenchyma being applied
      to tissue composed of cells with the walls hardened but
      not thickened, and sclerenchyma to tissue composed of
      cells with the walls both hardened and thickened.
      [1913 Webster]