1. devices that control the flow of fluids, gases, or other materials through pipes or passages by opening, closing, or partially obstructing them
2. flap-like structures in the heart and blood vessels that prevent blood from flowing backward
Usage: anatomy
3. hinged shells of mollusks such as clams and oysters
Usage: biology

Examples

• The plumber replaced the old valves in the water system.
• Turn the valves clockwise to shut off the gas supply.
• Heart valves ensure blood flows in the correct direction.
• The patient needed surgery to repair damaged heart valves.
• We found empty clam valves scattered along the beach.
• The oyster’s valves snapped shut when touched.
• Check all the valves before starting the engine.