knock off vs pluck

knock off

verb
  • To remove by hitting (something, someone) 

  • 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 kill. 

  • To accomplish hastily. 

pluck

verb
  • To take or remove (someone) quickly from a particular place or situation. 

  • To pull something sharply; to pull something out 

  • To pull or twitch sharply. 

  • To remove feathers from a bird. 

  • To play a string instrument pizzicato. 

  • To gently play a single string, e.g. on a guitar, violin etc. 

  • Of a glacier: to transport individual pieces of bedrock by means of gradual erosion through freezing and thawing. 

noun
  • Guts, nerve, fortitude or persistence. 

  • The lungs, heart with trachea and often oesophagus removed from slaughtered animals. 

  • An instance of plucking or pulling sharply. 

  • Cheap wine. 

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