- an investigative committee of the U.S. House of Representatives. Originally created in 1938 to inquire into subversive activities in the U.S., it was reestablished in 1945 as the Committee on Un-American Activities, renamed in 1969 as the Committee on Internal Security, and abolished in 1975. Abbreviation: HUAC
- the former name of the Internal Security Committee of the US House of Representatives: notorious for its anti-Communist investigations in the late 1940s and 1950s