life preserver vs truncheon

life preserver

noun
  • A buoyant ring or vest intended to keep a person afloat. 

truncheon

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

  • A short staff, a club; a cudgel. 

  • A penis. 

verb
  • To strike with a truncheon. 

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