hurt vs knock off

hurt

verb
  • To be painful. 

  • To cause (a person or animal) physical pain and/or injury. 

  • To cause (somebody) emotional pain. 

  • To damage, harm, impair, undermine, impede. 

adj
  • Wounded, physically injured. 

  • Pained. 

noun
  • A roundel azure (blue circular spot). 

  • A band on a trip hammer's helve, bearing the trunnions. 

  • A husk. 

  • An emotional or psychological humiliation or bad experience. 

knock off

verb
  • To kill. 

  • To rob. 

  • To defeat. 

  • To halt one's work or other activity. 

  • To have sex with. 

  • To remove, as a discount or estimate. 

  • To make a copy of, as of a design. 

  • To assign (an item) to a bidder at an auction, indicated by knocking on the counter. 

  • To remove by hitting (something, someone) 

  • To accomplish hastily. 

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