nullification vs retention

nullification

noun
  • 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. 

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

retention

noun
  • The portion of a potential damange that must be paid for by the holder of an insurance policy. 

  • The act or power of remembering things 

  • The involuntary withholding of urine and faeces 

  • A memory; what is retained in the mind 

  • The length of time an individual remains in treatment 

  • The right to withhold a debt, or of retaining property until a debt due to the person claiming the right is duly paid; a lien. 

  • The act of retaining or something retained 

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