[log.ic] n [ME logik, fr. MF logique, fr. L logica, fr. Gk logike, fr. fem. of logikos of reason, fr. logos reason--more at legend] (12c) 1 a (1): a science that deals with the principles and criteria of validity of inference and demonstration: the science of the formal principles of reasoning (2): a branch or variety of logic "modal ~" "Boolean ~" (3): a branch of semiotic; esp: syntactics (4): the formal principles of a branch of knowledge b (1): a particular mode of reasoning viewed as valid or faulty (2): relevance, propriety c: interrelation or sequence of facts or events when seen as inevitable or predictable d: the arrangement of circuit elements (as in a computer) needed for computation; also: the circuits themselves
2: something that forces a decision apart from or in opposition to reason "the ~ of war" -- lo.gi.cian n