What is the term for an individual who files a lawsuit against another party for alleged harm?

The term that is commonly used for an individual who files a lawsuit against another party for alleged harm is 'Plaintiff.' In a legal context, the plaintiff is the person or entity that initiates a lawsuit, expressing a grievance and seeking relief or damages through the legal system. This role is fundamental in civil law cases, where the plaintiff alleges that they have suffered harm and seeks a remedy from the court.

While other terms such as 'Defendant' and 'Complainant' may come into play in legal scenarios, they refer to different roles within the litigation process. The defendant is the party being accused in the lawsuit, while a complainant typically refers to someone who makes a formal complaint in civil or administrative proceedings, but may not always align with the legal definition of a plaintiff in the context of a lawsuit. 'Litigant' is a broader term that encompasses anyone involved in a lawsuit, which can include both the plaintiff and defendant. Thus, 'Plaintiff' is the specific term that accurately denotes the individual who brings forth a lawsuit.