Reservoir
Else clues• It may hold water
• It'll hold water
• Man-made reservoir
• Rain storage reservoir
• Rain storage tank
• Rainwater tank
• Tank
• Underground reservoir
• Underground tank
• Underground water tank
• Water reservoir
• Water storer
• Water tank
• Well
• Especially an underground tank for storing rainwater
• An artificial reservoir for storing liquids
• A tank that holds the water used to flush a toilet
• A sac or cavity containing fluid especially lymph or cerebrospinal fluid