mantrap vs smoke detector

mantrap

noun
  • A mechanical device for catching trespassers. 

  • A small space with two sets of interlocking doors, such that the first set of doors must close before the second set opens, used to restrict access. 

  • A woman who is dangerously seductive to men. 

smoke detector

noun
  • A device that sounds an alarm when it detects smoke or other evidence of fire. 

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