From Longman Dictionary of Contemporary EnglishHUAC, thethe HUACHUAC, the /ˈhjuːæk ˌeɪtʃ juː eɪ ˈsiː/ (the House Un-American Activities Committee) a group in the US House of Representatives which tried to find out whether US citizens were enemies of the government. It was especially active during the early 1950s as a result of McCarthyism. At this time, the Committee judged many cases involving politicians, military officers, and other well-known people who were believed to be communists. It stopped operating in 1975.