1. A device that automatically controls the flow or pressure of a liquid, especially water, in a system.
Usage: technical; engineering
2. An instrument that measures or detects the presence of moisture or water in a substance or environment.
Usage: technical; scientific

Examples

• The hydrostat in the heating system maintains consistent water pressure.
• Engineers installed a hydrostat to prevent overflow in the reservoir.
• The hydrostat automatically shut off the water supply when the tank reached capacity.
• A hydrostat sensor detected moisture in the basement after the storm.
• The building's plumbing system relies on a hydrostat for safe operation.