explosive vs pilot light

explosive

noun
  • Any explosive substance. 

adj
  • Easily driven to anger, usually with reference to a person. 

  • Shocking; startling. 

  • With the capability to, or likely to, explode. 

  • Having the character of an explosion. 

pilot light

noun
  • A small, persistent flame used to ignite gas. 

  • A small telltale lamp on a dynamo or battery circuit whose brightness indicates the voltage of the current. 

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