1. large tanks or reservoirs for storing water, especially rainwater

Examples

• The old house had two large cisterns in the basement for collecting rainwater.
• Many rural homes rely on cisterns to store their water supply.
• The cisterns were filled during the rainy season to last through the dry months.
• Workers inspected the underground cisterns for cracks and leaks.
• The school installed new cisterns to improve their water storage capacity.
• Ancient Roman cisterns can still be found beneath many European cities.