The Collaborative International Dictionary of English v.0.48:

Comparative \Com*par"a*tive\, a. [L. comparativus: cf. F.
   comparatif.]
   1. Of or pertaining to comparison. "The comparative faculty."
      --Glanvill.
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   2. Proceeding from, or by the method of, comparison; as, the
      comparative sciences; the comparative anatomy.
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   3. Estimated by comparison; relative; not positive or
      absolute, as compared with another thing or state.
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            The recurrence of comparative warmth and cold.
                                                  --Whewell.
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            The bubble, by reason of its comparative levity to
            the fluid that incloses it, would necessarily ascend
            to the top.                           --Bentley.
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   4. (Gram.) Expressing a degree greater or less than the
      positive degree of the quality denoted by an adjective or
      adverb. The comparative degree is formed from the positive
      by the use of -er, more, or less; as, brighter, more
      bright, or less bright.
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   Comparative sciences, those which are based on a
      comprehensive comparison of the range of objects or facts
      in any branch or department, and which aim to study out
      and treat of the fundamental laws or systems of relation
      pervading them; as, comparative anatomy, comparative
      physiology, comparative philology.
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The Collaborative International Dictionary of English v.0.48:

Anatomy \A*nat"o*my\, n.; pl. Anatomies. [F. anatomie, L.
   anatomia, Gr. ? dissection, fr. ? to cut up; ? + ? to cut.]
   1. The art of dissecting, or artificially separating the
      different parts of any organized body, to discover their
      situation, structure, and economy; dissection.
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   2. The science which treats of the structure of organic
      bodies; anatomical structure or organization.
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            Let the muscles be well inserted and bound together,
            according to the knowledge of them which is given us
            by anatomy.                           --Dryden.
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   Note: "Animal anatomy" is sometimes called zomy; "vegetable
         anatomy," phytotomy; "human anatomy," anthropotomy.
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   Comparative anatomy compares the structure of different
      kinds and classes of animals.
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   3. A treatise or book on anatomy.
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   4. The act of dividing anything, corporeal or intellectual,
      for the purpose of examining its parts; analysis; as, the
      anatomy of a discourse.
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   5. A skeleton; anything anatomized or dissected, or which has
      the appearance of being so.
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            The anatomy of a little child, representing all
            parts thereof, is accounted a greater rarity than
            the skeleton of a man in full stature. --Fuller.
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            They brought one Pinch, a hungry, lean-faced
            villain,
            A mere anatomy.                       --Shak.
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WordNet (r) 3.0 (2006):

comparative anatomy
    n 1: the study of anatomical features of animals of different
         species