- 1 quash something (law) to officially say that a decision made by a court is no longer valid or correct synonym overturn His conviction was later quashed by the State Supreme Court.
- 2quash something to take action to stop something from continuing synonym suppress The rumors were quickly quashed.
NAmE//kwɑʃ//Verb Forms present simple I / you / we / they quash
,he / she / it quashes
,past simple quashed
,-ing form quashing