Final answer:
McCarthyism refers to Senator Joseph McCarthy's tactics of making unfounded accusations of disloyalty without providing evidence during the Cold War period.
Step-by-step explanation:
McCarthyism refers to the anti-Communist hysteria and tactics employed by Wisconsin Senator Joseph McCarthy during the Cold War period. McCarthy would make unsubstantiated accusations of disloyalty against numerous individuals and government agencies without providing any evidence. This led to a climate of fear and suspicion, where anyone could be labeled a Communist sympathizer. McCarthy's tactics of accusation without evidence became emblematic of the era, and the term McCarthyism is now used to describe this type of political smear campaign.