boil vs touch hole

boil

noun
  • The point at which fluid begins to change to a vapour; the boiling point. 

  • A dish of boiled food, especially seafood. 

  • A social event at which people gather to boil and eat food, especially seafood. (Compare a bake or clambake.) 

  • The collective noun for a group of hawks. 

  • A localized accumulation of pus in the skin, resulting from infection. 

verb
  • To form, or separate, by boiling or evaporation. 

  • To feel uncomfortably hot. 

  • To be moved or excited with passion; to be hot or fervid. 

  • To bring to a boil, to heat so as to cause the contents to boil. 

  • To begin to turn into a gas, seethe. 

  • To heat to the point where it begins to turn into a gas. 

  • To be uncomfortably hot. 

  • To cook in boiling water. 

  • To be agitated like boiling water; to bubble; to effervesce. 

touch hole

noun
  • A small hole through which the propellant charge of a cannon or muzzleloading gun is ignited. 

How often have the words boil and touch hole occurred in a corpus of books? (source: Google Ngram Viewer )