Meaning of “quash” - Learner’s Dictionary

quash

verb [ T ] uk us /kwɒʃ/
CHANGE DECISION formal

to officially change a legal decision so that it stops existing:

His conviction was quashed last month.
STOP

to stop something that you do not want to happen:

He appeared on television to quash rumours that he was seriously ill.

(Definition of “quash” from the Cambridge Learner’s Dictionary © Cambridge University Press)