quash

To defeat decisively, to suppress.

• The army quashed the rebellion.

To crush or dash to pieces.obsolete

• The whales / Against sharp rocks, like reeling vessels, quashed, / Though huge as mountains, are in pieces dashed.

To void or suppress (a subpoena, decision, etc.).

• In the case of an appeal against conviction the Court shall, if they allow the appeal, quash the conviction.