Libellant is a term used in legal contexts to refer to a person who initiates a lawsuit or legal action against another party. Some potential synonyms for this word include plaintiff, petitioner, claimant, suer, complainant, and litigant. Each of these words describes a person who is bringing a legal matter to the attention of the court, but they may be used in slightly different contexts or legal systems. For example, plaintiff is a more commonly used term in American legal proceedings, while petitioner may be used more frequently in international or administrative law. However, all of these words can be used interchangeably with libellant, depending on the specific legal context in which they are being used.