shillelagh vs truncheon

shillelagh

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

  • Any cudgel, whether or not of Irish origin. 

truncheon

noun
  • A short staff, a club; a cudgel. 

  • A baton, or military staff of command, now especially the stick carried by a police officer. 

  • A penis. 

verb
  • To strike with a truncheon. 

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