Oklahoma Residential Real Property- Definition of Defect is a term used to describe any defect in a residential property that could significantly affect its value or use. This includes physical defects, such as structural damage or mold, as well as legal defects, such as zoning issues or title problems. Common types of Oklahoma Residential Real Property- Definition of Defect include: structural defects, water damage, mold, foundation problems, termite infestations, and title or legal issues.