renunciation

rejecting or disowning or disclaiming as invalid

Congressional repudiation of the treaty that the President had negotiated

the state of having rejected your religious beliefs or your political party or a cause (often in favor of opposing beliefs or causes)

an act (spoken or written) declaring that something is surrendered or disowned

the act of renouncing; sacrificing or giving up or surrendering (a possession or right or title or privilege etc.)