Interrogatory — a list of written questions about any nonprivileged matter that is relevant to claims and defenses at issue in the litigation submitted by one party (the plaintiff or the defendant) to the other party as part of the pretrial discovery process in a civil action. The recipient must answer the questions in writing, usually under oath within a specified period of time (for example, within 30 days after being served with the interrogatories). Answers to interrogatories are used to refine and clarify the issues and to focus on discrete theories and facts to develop the case for trial but cannot be used to elicit privileged information, such as communications between a party and its attorney.