cudgel vs shillelagh

cudgel

noun
  • A short heavy club with a rounded head used as a weapon. 

  • Anything that can be used as a threat to force one's will on another. 

verb
  • To strike with a cudgel. 

  • To exercise (one's wits or brains). 

shillelagh

noun
  • A wooden (traditionally blackthorn (sloe) wood) club ending with a large knob. 

  • Any cudgel, whether or not of Irish origin. 

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