regen vs revivify

regen

verb
  • To regenerate. 

noun
  • A regenerative radio receiver. 

  • Regeneration. 

revivify

verb
  • To reanimate, bring back to life. 

  • To reinvigorate or revitalize. 

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