Which word describes a property that is deserted by its owner and run-down?

The term that accurately describes a property that has been deserted by its owner and is in a state of disrepair is "dereliction." "Dereliction" refers specifically to the state of something that has been abandoned or neglected. This term conveys not only the idea of abandonment but also implies that the property is suffering from deterioration and a lack of maintenance.

In the context of real estate or urban environments, a derelict property often raises concerns regarding safety and aesthetics, and it may attract negative attention or require intervention to restore it. Therefore, using "dereliction" correctly captures both the abandonment and the run-down condition of the property in question.

The other terms present do not align with this specific meaning. For instance, "diffused" typically refers to something that is spread out or diluted and does not relate to property status. "Egregious" means outstandingly bad or shocking, which does not indicate abandonment or ruin. "Emblazon" refers to depicting or displaying something prominently and is unrelated to the condition of a property.