1. (大楼的)蓄水箱，水塔;(抽水马桶的)水箱
A cistern is a container which stores the water supply for a building, or that holds the water for flushing a toilet.

1. an artificial reservoir for storing liquids
especially an underground tank for storing rainwater

2. a tank that holds the water used to flush a toilet

Synonym: water tank

3. a sac or cavity containing fluid especially lymph or cerebrospinal fluid

Synonym: cisterna