'McCarthyism' definitions:

Definition of 'McCarthyism'

(from WordNet)
noun
Unscrupulously accusing people of disloyalty (as by saying they were Communists)

Definition of 'McCarthyism'

From: GCIDE
  • McCarthyism \McCarthyism\ prop. n. [from Senator Joseph McCarthy, who repeatedly asserted without evidence that numerous communists were present in the United States government.] Unscrupulously accusing people of disloyalty (as by saying they were Communists). [WordNet 1.5 +PJC]