knockback vs withholding

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. 

withholding

noun
  • The deduction of taxes from an employee's salary. 

  • The tax so deducted, and paid to local or national government. 

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