quashquash /kwɒʃkwɑːʃ, kwɒːʃ/ verb [transitiveT]1LAWto officially state that a judgement or decision is no longer legal or correctHe was found guilty but had his conviction quashed later on appeal.
2to stop something from starting or developingCar-rental companies say they quashed a state government plan to double Florida’s car rental surcharge.
A hospital chief executive has quashed rumours that nursing staff will lose jobs.