cooler vs immersion heater

cooler

noun
  • A bouncer or doorman. 

  • A cold deck. 

  • An insulated bin or box used with ice or freezer packs to keep food or beverages cold while picnicking or camping. 

  • Anything which cools. 

  • A device for refrigerating dead bodies in a morgue. 

  • A type of drink made with alcohol, especially wine, mixed with fruit juice. 

  • A prison. 

  • samalamig 

immersion heater

noun
  • A device for supplying domestic hot water in which a thermostatically-controlled heating element is immersed within a tank of water 

How often have the words cooler and immersion heater occurred in a corpus of books? (source: Google Ngram Viewer )