A more thorough explanation:

Defectus sanguinis means "defect of blood" in Latin. In history, it referred to a failure of issue, which often resulted in the reversion of land ownership back to the lord when the immediate tenant died without heirs. This is called an escheat. For example, if a lord granted land to a tenant, but the tenant died without any children or legal heirs, the land would go back to the lord. This was a way for the lord to maintain control over the land and prevent it from falling into the hands of someone outside of their control. Today, escheat can also refer to the reversion of property, especially real property, to the state upon the death of an owner who has neither a will nor any legal heirs. This means that if someone dies without a will and without any living relatives, their property will go to the state.