The close or last part; the end or finish: the conclusion of the festivities. The result or outcome of an act or process: What was the conclusion of all these efforts? A judgment or decision reached after deliberation. See Synonyms at decision. A final arrangement or settlement, as of a treaty. Law The formal closing of a legal complaint or pleading. Logic A proposition that follows from the premises of a formal proof, for instance from the major and minor premises of a syllogism. The proposition concluded from one or more premises; a deduction.