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]

WordNet (r) 3.0 (2006):

hibernate
    v 1: sleep during winter; "Bears must eat a lot of food before
         they hibernate in their caves" [syn: hibernate, hole
         up] [ant: aestivate, estivate]
    2: be in an inactive or dormant state

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "hibernate":
   aestivate, be a sideliner, be latent, be still, coast, delay,
   do nothing, drift, escape notice, hang fire, have nothing on, idle,
   lay by, lay off, lay to, lie beneath, lie by, lie dormant,
   lie fallow, lie hid, lie idle, lie low, lie off, lie to, lie up,
   lurk, make no sign, not budge, not stir, rest, ride at anchor,
   sit back, sit it out, smolder, stagnate, underlie, vegetate,
   wait and see, watch and wait



The Devil's Dictionary (1881-1906):

HIBERNATE, v.i.  To pass the winter season in domestic seclusion.
There have been many singular popular notions about the hibernation of
various animals.  Many believe that the bear hibernates during the
whole winter and subsists by mechanically sucking its paws.  It is
admitted that it comes out of its retirement in the spring so lean
that it had to try twice before it can cast a shadow.  Three or four
centuries ago, in England, no fact was better attested than that
swallows passed the winter months in the mud at the bottom of their
brooks, clinging together in globular masses.  They have apparently
been compelled to give up the custom and account of the foulness of
the brooks.  Sotus Ecobius discovered in Central Asia a whole nation
of people who hibernate.  By some investigators, the fasting of Lent
is supposed to have been originally a modified form of hibernation, to
which the Church gave a religious significance; but this view was
strenuously opposed by that eminent authority, Bishop Kip, who did not
wish any honors denied to the memory of the Founder of his family.