noun (n)

• withdrawing support or help despite allegiance or responsibility(noun.act)

  Synonym:
  abandonment, desertion
  

  source: wordnet30
• the state of having rejected your religious beliefs or your political party or a cause (often in favor of opposing beliefs or causes)(noun.state)

  Synonym:
  apostasy, renunciation
  

  source: wordnet30
• Act of abandoning a person or cause to which one is bound by allegiance or duty, or to which one has attached himself; desertion; failure in duty; a falling away; apostasy; backsliding.(noun)

  source: webster1913