Main Entry: cis·tern

Pronunciation: \ˈsis-tərn\

Function: noun

Etymology: Middle English, from Latin cisterna, from cista box, chest — more at chest

Date: 13th century

1 : an artificial reservoir (as an underground tank) for storing liquids and especially water (as rainwater)
2 : a large usually silver vessel formerly used (as in cooling wine) at the dining table
3 : a fluid-containing sac or cavity in an organism