House Un-American Activities Committee in British English
noun
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
House Un-American Activities Committee in American English
noun
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