knockback vs renunciation

knockback

noun
  • A rejection; a refusal. 

  • A blow that causes the recipient to fall or move backwards, a knock back; a recoil. 

  • Something that impedes or reverses progress; a setback. 

renunciation

noun
  • The act of rejecting or renouncing something as invalid. 

  • The resignation of an ecclesiastical office. 

  • In the Anglican baptismal service, the part in which the candidate in person or by his sureties renounces the Devil and all his works. 

  • The act by which a person abandons a right acquired, but without transferring it to another. 

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