cistern vs pod

cistern

noun
  • The vessel surrounding the condenser in a steam engine. 

  • In a flush toilet, the container in which the water used for flushing is held; a toilet tank. 

  • A cisterna. 

  • A reservoir or tank for holding water, especially for catching and holding rainwater for later use. 

pod

noun
  • A small vehicle, especially used in emergency situations. 

  • A lie-flat business or first class seat. 

  • A small section of a larger office, compartmentalised for a specific purpose. 

  • A subsection of a prison, containing a number of inmates. 

  • A seed case for legumes (e.g. peas, beans, peppers); a seedpod. 

  • A group of whales, dolphins, seals, porpoises or hippopotami. 

  • A nicotine cartridge. 

verb
  • To swell or fill. 

  • To remove peas from their case. 

  • To put into a pod or to enter a pod. 

  • To bear or produce pods 

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