The Collaborative International Dictionary of English v.0.48:

Hibernate \Hi"ber*nate\, v. i. [imp. & p. p. Hibernated; p.
   pr. & vb. n. Hibernating.] [L. hibernare, hibernatum, fr.
   hibernus wintry. See Hibernal.]
   To winter; to pass the season of winter in close quarters, in
   a torpid or lethargic state, as certain mammals, reptiles,
   and insects.
   [1913 Webster]

         Inclination would lead me to hibernate, during half the
         year, in this uncomfortable climate of Great Britain.
                                                  --Southey.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

hibernating \hibernating\ adj.
   in a state of suspended animation; -- of animals that sleep
   most of the winter. [prenominal]

   Syn: dormant, torpid.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

hibernating
    adj 1: in a condition of biological rest or suspended animation;
           "dormant buds"; "a hibernating bear"; "torpid frogs"
           [syn: dormant, hibernating(a), torpid]