Search Result for "mccarthyism": 
Wordnet 3.0

NOUN (1)

1. unscrupulously accusing people of disloyalty (as by saying they were Communists);


The Collaborative International Dictionary of English v.0.48:

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]
WordNet (r) 3.0 (2006):

McCarthyism n 1: unscrupulously accusing people of disloyalty (as by saying they were Communists)