The Collaborative International Dictionary of English v.0.48:

Palingenesis \Pal`in*gen"e*sis\, Palingenesy \Pal`in*gen"e*sy\,
   n. [Gr. ?; pa`lin again + ? birth: cf. F. paling['e]n['e]sie.
   See Genesis.]
   [1913 Webster]
   1. A new birth; a re-creation; a regeneration; a continued
      existence in different manner or form.
      [1913 Webster]

   2. Hence: The passing over of the soul of one person or
      animal into the body of another person or animal, at the
      time of the death of the first; the transmigration of
      souls. Called also metempsychosis.
      [PJC]

   3. (Biol.) That form of development of an individual organism
      in which in which ancestral characteristics occurring
      during its evolution are conserved by heredity and
      reproduced, sometimes transiently, in the course of
      individual development; original simple descent; --
      distinguished from cenogenesis (kenogenesis or
      coenogenesis), in which the mode of individual
      development has been modified so that the evolutionary
      process had become obscured. Sometimes, in Zoology, the
      term is applied to the abrupt metamorphosis of insects,
      crustaceans, etc. See also the note under
      recapitulation.
      [1913 Webster +PJC]

The Collaborative International Dictionary of English v.0.48:

Metempsychosis \Me*temp`sy*cho"sis\, n. [NL., fr. Gr. ?; ?
   beyond, over + ? to animate; ? in + ? soul. See
   Psychology.]
   The passage of the soul, as an immortal essence, at the death
   of the animal body it had inhabited, into another living
   body, whether of a brute or a human being; transmigration of
   souls. --Sir T. Browne.
   [1913 Webster]

WordNet (r) 3.0 (2006):

metempsychosis
    n 1: after death the soul begins a new cycle of existence in
         another human body [syn: metempsychosis, rebirth]