retrocession vs reversal

retrocession

noun
  • The act of retroceding; a going back. 

  • The transfer of risk from one reinsurer to another. 

  • The return of land, rights, etc. previously ceded. 

  • Metastasis of an eruption or tumour from the surface to the interior of the body. 

reversal

noun
  • The state of being reversed. 

  • A change in fortune; a change from being successful to having problems. 

  • An instance of reversing. 

adj
  • Intended to reverse; implying reversal. 

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