double boiler vs poach

double boiler

noun
  • A pair of interlocking pots, the lower one filled with water which when boiling heats the contents of the upper pot. 

  • A large pan containing hot water, into which other smaller pans are set in order to cook food at low heat (below the boiling point) or to keep food warm. 

poach

noun
  • The act of cooking in simmering liquid. 

  • The act of taking something unfairly, as in tennis doubles where one player returns a shot that their partner was better placed to return. 

verb
  • To take game or fish illegally. 

  • To take anything illegally or unfairly. 

  • To become soft or muddy by being trampled on. 

  • To cook something in simmering liquid. 

  • To be cooked in simmering liquid 

  • To entice (an employee or customer) to switch from a competing company to one's own. 

  • To intrude; to interfere; to get involved inappropriately, without welcome. 

  • To make soft or muddy by trampling. 

  • To trespass on another's property to take fish or game. 

How often have the words double boiler and poach occurred in a corpus of books? (source: Google Ngram Viewer )