Calumny, says the New Oxford American Dictionary, is “the making of false and defamatory statements in order to damage someone's reputation; slander.”

What is severe calumny?

a false and malicious statement designed to injure the reputation of someone or something: The speech was considered a calumny of the administration. the act of uttering calumnies; slander; defamation.

Whats the definition of calumny?

1 : a misrepresentation intended to harm another's reputation denounced his opponent for his defamatory insinuations and calumny. 2 : the act of uttering false charges or misrepresentations maliciously calculated to harm another's reputation He was the target of calumny for his unpopular beliefs.