Entry: the period of the Cold War (late 1940's and early 1950's) during which U.S. Senator Joseph McCarthy pursued American citizens whom he and his followers suspected of being members or former members of, or sympathizers with, the Communist Party. His efforts included the creation of "blacklists" in various professions - - roster of people who were excluded from working in those jobs. McCarthy ultimately was denounced by his Senate colleagues.
@ Milton-Kindersley Advanced Dictionary