From Longman Dictionary of Contemporary Englishcisterncis‧tern /ˈsɪstən $ -ərn/ noun [countable] DHHa container in which the supply of water for a building is stored inside the building SYN tank
Examples from the Corpus
cistern• Each kit comprises a cistern dam and a ball arm extension. 1 Lift off the cistern lid.• The roofs of houses drained into the internal courts, the water being collected in a cistern beneath.• Lakes and ponds were tapped, water from the Lys sterilized and stored in barges, and cisterns built to trap rainwater.• At lunchtime I take my Colefax & Fowler bag and change it for the one hidden above the cistern.• This prevents any vibration caused by the cistern being filled from being transmitted back down the rising main.• The cistern of his lav is adorned with the hammer and sickle while the stars and stripes is also strategically placed.• Father-of-two Ian Cadwaller found £800 tucked into a toilet cistern.Origin cistern (1200-1300) Old French cisterne, from Latin cisterna, from cista “box” 