Source : Webster's Revised Unabridged Dictionary (1913)

Defection \De*fec"tion\, n. [L. defectio: cf. F. d['e]fection.
   See {Defect}.]
   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. ``Defection and falling away from God.'' --Sir
   W. Raleigh.

         The general defection of the whole realm. --Sir J.
                                                  Davies.

Source : WordNet®

defection
     n 1: withdrawing support or help despite allegiance or
          responsibility; "his abandonment of his wife and
          children left them penniless" [syn: {desertion}, {abandonment}]
     2: the state of having rejected your religious beliefs or your
        political party or a cause (often in favor of opposing
        beliefs or causes) [syn: {apostasy}, {renunciation}]