defect

Definition from Nolo’s Plain-English Law Dictionary

An imperfection in a product, machinery, process, or written document that makes the item unusable or harmful, such as faulty brakes in a car, or invalid, such as a deed signed by someone who does not have title to the property. A defect may also be minor, such as scratches on a car door, that lessens value or use of the item, but does not make it dangerous or useless.

Definition provided by Nolo’s Plain-English Law Dictionary.