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.
      [1913 Webster]

WordNet (r) 3.0 (2006):

varying hare
    n 1: large large-footed North American hare; white in winter
         [syn: snowshoe hare, snowshoe rabbit, varying hare,
         Lepus americanus]