quisling
noun /ˈkwɪzlɪŋ/
/ˈkwɪzlɪŋ/
(disapproving)- a person who helps an enemy that has taken control of his or her country synonym collaboratorWord OriginSecond World War: from the name of Major Vidkun Quisling (1887–1945), the Norwegian army officer and diplomat who ruled Norway on behalf of the German occupying forces (1940–45).