regen vs restitute

regen

verb
  • To regenerate. 

noun
  • A regenerative radio receiver. 

  • Regeneration. 

restitute

verb
  • To restore (something) to its former condition. 

  • To provide recompense for (something). 

  • To refund. 

noun
  • That which is restored or offered in place of something; a substitute. 

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