Calumniously is an adverb that describes something done in a false and harmful way, with the intention to damage someone else's reputation. There are several synonyms for this word that can be used interchangeably in written and spoken communication. One synonym is slanderously, which implies the spreading of false and damaging information about someone. Another synonym is defamatorily, which refers to the act of harming someone's reputation through false accusations or statements. A third synonym is disparagingly, which suggests a negative attitude towards someone, which results in comments or actions that harm their reputation or standing in the community. All these synonyms convey the sense of wrongdoing and harm done to someone else's reputation, and can be useful in conveying that message in a clear and effective way.