noun
- a small valve used to drain or release liquid or gas from a tank, pipe, or engine
Usage: mechanical; automotive
Examples
- The mechanic opened the petcock to drain the radiator fluid.
- Check the petcock at the bottom of the water heater for leaks.
- Turn the petcock counterclockwise to release the pressure.
- The old petcock was corroded and needed replacement.
- She closed the petcock tightly after draining the system.
- The petcock allows you to empty the tank completely.