A more thorough explanation:

Definition: Ex defectu juris is a Latin term used in Scots law, which means "from a defect in the right." It refers to the legal obligation of a seller to warrant a purchaser against eviction based on a defect in the seller's own right.

Example: If a person sells a property to another person, they must ensure that they have the legal right to sell the property. If the seller does not have the legal right to sell the property, and the purchaser is evicted from the property, the seller is responsible for compensating the purchaser for any losses incurred.

EX DEFECTU NATALIUM

Definition: Ex defectu natalium is a Latin term used in historical legal contexts, which means "from defect of parentage." It refers to a basis upon which the court rejected the will of a bastard who died without issue.

Example: In the past, if a person who was born out of wedlock died without any children, their will could be rejected by the court if there were any defects in their parentage. This means that if the person's parents were not legally married, their will could be invalidated.

These examples illustrate how the term "ex defectu" is used in legal contexts to refer to defects or flaws in legal rights or parentage that can have legal consequences.