Both untrue and harmful to a reputation.(adjective)
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Use "slanderous" in a sentence
"The Vatican denounced what it called a "slanderous campaign" against the Roman Catholic Church over the actions of Pope Pius XII during the Holocaust."
"Criticize the stands on issues as you like, but to characterize Jeff in slanderous terms is both patently false and an affront to those who choose to read your blog."
"Means "slanderous" - suggests that the ancient devil defamed people through word and deed"