Res adjudicata is a term used in legal circles that refers to a matter that has already been adjudicated, or settled in a court of law. There are several synonyms for this term, including "final judgment," "conclusive decision," "decreed matter," and "determined case." Res adjudicata is an important legal concept because it prevents parties from re-litigating the same issues that have already been resolved. This principle is designed to promote the finality of legal decisions and to prevent endless litigation. In short, res adjudicata is a Latin term that describes the final and binding nature of legal judgments.