SUBPOENA - An order directed to an individual commanding him to appear in court on a certain day to testify or produce documents in a pending lawsuit.

A process to cause a witness to appear and give testimony, commanding him to lay aside all pretences and excuses, and appear before a court or magistrate therein named, at a time therein mentioned, to testify for the party named, under a penalty therein mentioned. This is usually called a subpoena ad testificandum.

On proof of service of a subpoena upon the witness, and that he is material, an attachment way be issued against him for a contempt, if he neglect to attend as commanded.

chancery practice. A mandatory writ or process, directed to and requiring one or more persons to appear at a time to come, and answer the matters charged against him or them; the writ of subpoena was originally a process in the courts of common law, to enforce the attendance of a witness to give evidence; but this writ was used in the court of chancery for the game purpose as a citation in the courts of civil and canon law, to compel the appearance of a defendant, and to oblige him to answer upon oath the allegations of the plaintiff.