stylet vs switchblade

stylet

noun
  • A slender medical probe or device. 

  • A style of a plant's flower. 

  • A stiff, slender organ of an animal. 

  • An engraving tool, a stylus. 

  • A poniard or stiletto. 

switchblade

noun
  • A folding knife with a blade which opens automatically (under spring pressure) when a button is pressed. 

verb
  • To (cause to) make a sudden move or transition. 

  • To attack or cut with a switchblade. 

  • To spring open or up. 

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