missile vs tear gas

missile

noun
  • Any object used as a weapon by being thrown or fired through the air, such as stone, arrow or bullet. 

  • A self-propelled projectile whose trajectory can be adjusted after it is launched. 

tear gas

verb
  • To use tear gas. 

noun
  • Any lachrymatory, non-lethal chemical compound that causes the eyes to sting and water and/or irritates the respiratory system, mostly used for controlling crowds during riots or as self-defense. 

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