quash
/kwɒʃ/verb
with obj.
1- reject as invalid, especially by legal procedure废止; 宣布无效：
his conviction was quashed on appeal.
上诉后他的判决被撤销。
1.1
- put an end to; suppress结束, 终止; 镇压, 平息：
a hospital executive quashed rumours that nursing staff will lose jobs.
一位医院管理人员平息了护理人员将要失业的谣言。
词源
Middle English: from Old French quasser 'annul'， from late Latin cassare （medieval Latin also quassare）， from cassus 'null， void'. Compare with SQUASH1.