cut off vs knap

cut off

verb
  • To interrupt (someone speaking). 

  • To remove via cutting. 

  • To turn off or switch off (an electrical device). 

  • (North American) swerve in front of (another car) while driving; cut [someone] up 

  • To isolate or remove from contact. 

  • To end abruptly. 

  • To stop providing funds to (someone). 

  • To stop the provision or supply of something, e.g. power, water. 

knap

verb
  • To make a sound of snapping. 

  • To rap or strike sharply. 

  • To shape a brittle material having conchoidal fracture, usually a mineral (flint, obsidian, chert etc.), by breaking away flakes, often forming a sharp edge or point. 

noun
  • A protuberance; a swelling; a knob. 

  • A small hill 

  • A sharp blow or slap. 

  • The crest of a hill 

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