1. General: Belief or mental state that does not conform to objective reality; where what is correct is actually incorrect and what is incorrect is actually correct. Often used interchangeably with mistake.
2. Law: Specific miscalculation or flaw in the basis, procedure, judgment, or execution of a court action, wording of a document, or recording of a statement.
3. Statistics: Deviation from a model, norm, specification, or standard that is not due to a lack of knowledge.