What is the act of making a false accusation against someone's character or reputation?

The term that describes the act of making a false accusation against someone's character or reputation is "calumny." This word specifically refers to the malicious act of spreading false statements intended to harm someone's reputation. It has its roots in Latin, where it conveys the idea of slander or defamation.

In contexts involving personal or professional relationships, an act of calumny can lead to serious consequences for the victim, as it undermines their credibility and can lead to social or occupational setbacks. By understanding this term, one can better recognize the severity and implications of spreading falsehoods about individuals.

The other terms do not pertain to false accusations. For instance, "denouement" refers to the conclusion or resolution of a narrative, "captious" relates to being overly critical or fault-finding, and "cozen" means to cheat or deceive through trickery. Each of these words has distinct meanings that do not align with the idea of harming someone's reputation through false accusations.