key fob vs necklace

key fob

noun
  • An item carried on a key ring either as decoration or security. 

  • A passive wireless electronic device that usually uses RFID technology to control access to buildings, containers, computers, etc. by being placed near a detector. 

  • An active wireless electronic device that controls access to buildings or vehicles, such as a remote control for a car door lock. 

necklace

noun
  • An article of jewelry that is worn around the neck, most often made of a string of precious metal, pearls, gems, beads or shells, and sometimes having a pendant attached. 

  • Anything resembling a necklace in shape. 

  • A device used in necklacing (an informal execution); a rubber tyre that is filled with petrol. It is placed around the victim's chest and arms, and set on fire. 

verb
  • To informally execute by necklacing; by setting on fire a petrol-filled rubber tyre which has been put around the bound victim's neck. 

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