a device for regulating the flow of a liquid into a tank, cistern, etc, consisting of a floating ball mounted at one end of an arm and a valve on the other end that opens and closes as the ball falls and rises with the water level in the cistern
Examples of 'ballcock' in a sentence
ballcock
All it took was an adjustment to the ballcock.
Times, Sunday Times (2017)
This is an important question not only for those looking for someone to fettle their ballcock.