nullification vs reversal

nullification

noun
  • The act of nullifying; a rendering void and of no effect, or no legal effect. 

  • The nullification crisis in U.S. history, confrontation between the state of South Carolina and the federal government in 1832–33 over the former's attempt to declare null and void within the state the federal Tariffs of 1828 and 1832. 

  • Surgical removal of genitals (and sometimes nipples) as a form of body modification; a person who has undergone this surgery is a nullo. 

reversal

noun
  • An instance of reversing. 

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

  • The state of being reversed. 

adj
  • Intended to reverse; implying reversal. 

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