knock back vs repulse

knock back

verb
  • To reject; to refuse. 

  • To drink an alcoholic beverage swiftly or often. 

  • To stun; to surprise. 

  • To press or knead (dough) so as to remove air bubbles. 

repulse

verb
  • To reject or rebuff. 

  • To repel or drive back. 

  • To cause revulsion in. 

noun
  • the act of repulsing or the state of being repulsed 

  • refusal, rejection or repulsion 

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