harpoon vs tear gas

harpoon

verb
  • To shoot something with a harpoon. 

noun
  • A spearlike weapon with a barbed head used in hunting whales and large fish. 

  • A harmonica. 

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. 

verb
  • To use tear gas. 

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