palingenesis vs regen

palingenesis

noun
  • Rebirth; regeneration; (countable) an instance of this. 

  • Spiritual rebirth through the transmigration of the soul. 

  • The recurrence of historical events in the same order in an infinite series of cycles. 

  • The regeneration of magma by the melting of metamorphic rocks. 

regen

noun
  • Regeneration. 

  • A regenerative radio receiver. 

verb
  • To regenerate. 

How often have the words palingenesis and regen occurred in a corpus of books? (source: Google Ngram Viewer )