1) written legal argument, usually in a format prescribed by the courts, stating the legal reasons for the suit based on statutes, regulations, case precedents, legal texts, and reasoning applied to facts in the particular situation 2)  to summarize a precedent, case, or lay out in writing a legal argument; attentive law students "brief" each case in their casebooks, which means extracting the rule of law, the reasoning (rationale), the essential facts, and the outcome. 3) to give a summary of important information to another person