The Collaborative International Dictionary of English v.0.48:

Vary \Va"ry\, v. t. [imp. & p. p. Varied; p. pr. & vb. n.
   Varying.] [OE. varien, F. varier, L. variare, fr. varius
   various. See Various, and cf. Variate.]
   [1913 Webster]
   1. To change the aspect of; to alter in form, appearance,
      substance, position, or the like; to make different by a
      partial change; to modify; as, to vary the properties,
      proportions, or nature of a thing; to vary a posture or an
      attitude; to vary one's dress or opinions.
      [1913 Webster]

            Shall we vary our device at will,
            Even as new occasion appears?         --Spenser.
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   2. To change to something else; to transmute; to exchange; to
      alternate.
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            Gods, that never change their state,
            Vary oft their love and hate.         --Waller.
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            We are to vary the customs according to the time and
            country where the scene of action lies. --Dryden.
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   3. To make of different kinds; to make different from one
      another; to diversify; to variegate.
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            God hath varied their inclinations.   --Sir T.
                                                  Browne.
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            God hath here
            Varied his bounty so with new delights. --Milton.
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   4. (Mus.) To embellish; to change fancifully; to present
      under new aspects, as of form, key, measure, etc. See
      Variation, 4.
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The Collaborative International Dictionary of English v.0.48:

Varying \Va"ry*ing\,
   a. & n. from Vary.
   [1913 Webster]

   Varying hare (Zool.), any hare or rabbit which becomes
      white in winter, especially the common hare of the
      Northern United States and Canada.
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WordNet (r) 3.0 (2006):

varying
    adj 1: marked by diversity or difference; "the varying angles of
           roof slope"; "nature is infinitely variable" [syn:
           varying, variable]