COLLATERAL MATTER

collateral matter.Evidence. Any matter on which evidence could not have been introduced for a relevant purpose. • If a witness has erred in testifying about a detail that is collateral to the relevant facts, then another party cannot call witnesses to contradict that point — cross-examination alone must suffice. [Cases: Evidence  99; Wit-nesses  405. C.J.S. Evidence §§ 2–5, 197–199, 204, 206; Witnesses § 770.] [Blacks Law 8th]