Final answer:
Bone erosions with thin "overhanging" edges seen on XR are known as "rat bite" erosions and are often associated with chronic rheumatoid arthritis.
Step-by-step explanation:
The radiological finding described as bone erosions with thin "overhanging" edges on x-ray (XR) is typically referred to as "rat bite" erosions.
This type of erosion is often associated with chronic rheumatoid arthritis, where the inflamed synovium erodes into the bone. These erosive changes on XR can help clinicians to diagnose and assess the severity of diseases that affect the bones.