A calumny is a lie about a person told to ruin their character. It is also the name of the act of lying about someone. It is synonymous with slander. Though when someone is falsely accused of a crime, calumny is a more appropriate word.
Its plural is calumnies. It also makes the adjective calumnious, the adverb caluminously, and the verb caluminate. The verb form appears as caluminated and calumniating, and makes the noun calumniation. One can also be a caluminator.