hibernation
  過冬,冬眠,避寒
  hi·ber·na·tion /ˌhaɪbɝˈneʃən/ 名詞
  冬眠
  hibernation
  冬眠
  Hi·ber·na·tion n.  The act or state of hibernating.
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  hibernation
       n 1: the torpid or resting state in which some animals pass the
            winter
       2: cessation from or slowing of activity during the winter;
          especially slowing of metabolism in some animals
       3: the act of retiring into inactivity; "he emerged from his
          hibernation to make his first appearance in several years"