Simple past tense and past participle of defect.(verb)
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Use "defected" in a sentence
"Charlie Crist, who last week defected from the GOP to run as an Independent."
"“People here are perplexed and wondering why Canada is rolling back the clock and depriving women in developing countries from having the same rights to basic health care and access to abortion as women in Canada,” said Keith Martin, a Liberal MP who defected from the Tories in 2004."
"Kenney defected from the Liberals to the Reform Party of Canada, a group that suggested in their 1990 Bluebook, Principles and Policies, that any immigration that altered the ethnic make-up of Canada should be rejected."