放棄【ほうき】
abandonment, renouncement, renunciation, resignation, abdication, surrender, relinquishing, waiving, giving up
棄権【きけん】
abstention (from voting), renunciation (of a right), withdrawal (from a contest)
棄却【ききゃく】
rejection, dismissal, turning down, abandoning, renunciation
破棄【はき】
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
廃棄【はいき】
disposal, abandonment, scrapping, discarding, abolition, annulment, cancellation, abrogation, repeal
投棄【とうき】
abandonment, giving up, throwing away, disposal, dumping
遺棄【いき】
abandonment, desertion
自暴自棄【じぼうじき】
desperation, despair, self-abandonment