arbalest vs trebuchet

arbalest

noun
  • A crossbow. 

  • A crossbowman. 

trebuchet

noun
  • A torture device for dunking suspected witches by means of a chair attached to the end of a long pole. 

  • A medieval siege engine consisting of a large pivoting arm heavily weighted on one end. 

verb
  • To shoot with a trebuchet. 

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