1) An exception to a zoning ordinance, usually granted by a local government. For example, if you own an oddly shaped lot that could not accommodate a house in accordance with your city's setback requirement, you could apply at the appropriate office (usually the zoning or planning department) for a variance allowing you to build closer to a boundary line. 2) In criminal cases, a discrepancy between what is alleged in the charges and what the prosecution produces as proof. If the judge or jury has nevertheless convicted the defendant, an appellate court may find that the discrepancy is a "fatal variance," requiring reversal. 3) In civil cases, the disparity between the plaintiff's claims (or allegations) and the proof that the plaintiff has produced. Modern pleading rules allow plaintiffs to amend their claims even during trial, to conform with the evidence they produce.