Definition of "quash"

Contrition is apt to quash or allay all worldly grief.

a. 1678 (date written), Isaac Barrow, “(please specify the chapter name or sermon number). Of Contentment”, in The Works of Dr. Isaac Barrow. […], volumes (please specify |volume=I to VII), London: A[braham] J[ohn] Valpy, […], published 1830–1831

Anne that she had been perfectly right in her proceedings, since, by quashing all idle hopes, both parties would see the necessity of conquering their foolish passion.

1838 (date written), L[etitia] E[lizabeth] L[andon], chapter XXI, in Lady Anne Granard; or, Keeping up Appearances. […], volume I, London: Henry Colburn, […], published 1842, page 269

the quashing of a jihadi enclave here only spurs the sprouting of another there

2014 November 17, Roger Cohen, “The horror! The horror! The trauma of ISIS ”, in The New York Times‎

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

1645, Edmund Waller, The Battle Of The Summer Islands

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

1968, Parliament of the United Kingdom, “Section 2(2)”, in Criminal Appeal Act 1968‎s:Criminal Appeal Act 1968, page 2