What does McCarthyism mean?

McCarthyism refers to the time period in the early 1950s when Senator Joseph McCarthy from Wisconsin claimed there were communists in all levels of our government.
After World War II ended, fears arose that the communists had infiltrated our government. Alger Hiss was convicted of perjury. When Igor Gouzenko defected to Canada, he said that communists were trying to infiltrate our and Canada’s government. The Loyalty Review Program, which was developed to determine if government employees were loyal to our country, led to some people losing their jobs.
Senator McCarthy began to hold hearings to investigate these concerns. He intimidated and bullied witnesses. He would wave a handful of papers in his hand, claiming he had the names of many people who were communist or who supported the communists. People were afraid to challenge him because he would claim they also were communist. This could ruin a person’s reputation.
When McCarthy claimed there were communists in the army, an attorney for the army challenged him. This attorney asked McCarthy if he had any sense of decency. Many Americans turned on Senator McCarthy. They saw how he operated when the hearings were televised, and they weren’t pleased with his tactics. Eventually, the Senate censured him. His power had been broken.
https://www.history.com/this-day-in-history/truman-orders-loyalty-checks-of-federal-employees

https://www.ushistory.org/us/53a.asp