Which term refers to a document formally issued to initiate a lawsuit?

The term that refers to a document formally issued to initiate a lawsuit is a summons. A summons serves as a legal notification to the defendant that a lawsuit has been filed against them and typically outlines the essential details of the case, including the court in which the case has been filed and the timeline within which the defendant must respond.

This document is crucial in the legal process, as it formally alerts the involved parties and initiates the proceedings in court. The summons ensures that the defendant is aware of the claims against them and has the opportunity to prepare their defense.

In contrast, a motion is a formal request made to the court for a specific ruling or order during the course of a lawsuit. A pleading is a more general term that refers to various formal documents submitted in court, such as complaints or answers, detailing the parties' claims and defenses. An affidavit is a written statement confirmed by oath or affirmation, used as evidence in court, but it does not initiate a lawsuit by itself.