Lacking in blood vessels or having a poor blood supply: Avascular necrosis is the death of body tissue because the blood supply has been cut off.

Dr. MacSween told Ralph that the avascular blood vessels and other tissues in his body were unable to provide sufficient blood to his bones and other body organs.

Some plants can also have avascular systems which are not able to carry sufficient water and nutrients throughout their systems.

Dead bone tissue because of an impaired or disrupted blood supply: One kind of avascular necrosis is that which is caused by a traumatic injury or disease and it is marked by severe pain in the affected region and by weakened bone (osteonecrosis) that may flatten and collapse.