cistern vs vat

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. 

vat

noun
  • A vessel for holding holy water. 

  • A square, hollow place on the back of a calcining furnace, where tin ore is laid to dry. 

  • A large tub, such as is used for making wine or for tanning. 

verb
  • To put into a vat. 

  • To blend (wines or spirits) in a vat; figuratively, to mix or blend elements as if with wines or spirits. 

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