In legal terms, what is a party called that does not initiate a lawsuit?

The term used to refer to a party that does not initiate a lawsuit is "defendant." In legal contexts, the defendant is the individual or group being accused or sued in a court of law. They are the parties that respond to the claims made against them by the plaintiff, who is the one initiating the lawsuit.

The distinction is significant, as the plaintiff is responsible for bringing the case forward, while the defendant is tasked with defending against the allegations. This definition is crucial in understanding the roles within legal proceedings, as each party has specific responsibilities and rights under the law.