tearing up and discarding (e.g. documents), destruction, annulment, cancellation, abrogation, voiding, breaking (e.g. a treaty), reversal (of an original ruling on appeal), quashing
自暴自棄【じぼうじき】
desperation, despair, self-abandonment
放棄【ほうき】
abandonment, renouncement, renunciation, resignation, abdication, surrender, relinquishing, waiving, giving up