defection

n. desertion, abandonment, disloyalty, changing sides

For other senses of this word, see defector (disambiguation).In politics, a defector is a person who gives up allegiance to one state or political entity in exchange for allegiance to another. The term is sometimes used as a synonym for traitor, especially if the defector brings with him secrets or confidential information. More broadly, it involves abandoning a person, cause or doctrine to whom or to which one is bound by some tie, as of allegiance or duty.
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Noun
1. withdrawing support or help despite allegiance or responsibility; "his abandonment of his wife and children left them penniless"
(synonym) desertion, abandonment
(hypernym) withdrawal
(hyponym) abscondment, decampment
(derivation) defect, desert
2. the state of having rejected your religious beliefs or your political party or a cause (often in favor of opposing beliefs or causes)
(synonym) apostasy, renunciation
(hypernym) rejection
(derivation) defect, desert

n. desertion, defection

(n.)
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.