Meaning of DEFECT in English

DEFECT

(LEAVE) [verb] [I] - to leave a country, political party, etc., esp. in order to join an opposing oneWhen the national hockey team visited America, half the players defected.The British spy, Kim Philby, defected to the Soviet Union/defected from Britain in 1963.

Cambridge English vocab.      Кембриджский английский словарь.