Used to label an unusually large number of occurrances of a disease or condition in one place. An autism cluster would be an unusually large number of cases of autism in (perhaps) a single locality. Clusters constitute evidence in the search for causes of diseases and conditions.
Top definition. jawn. a word used by Philly cats to describe anything and everything. NY cats interject with the word joint but it doesn't convey the same feelings.
Osteoradionecrosis (ORN) of the jaw is one of the main complications of radiotherapy, and results in alteration of the shape and function of the oral cavity and jaw that causes substantial deterioration in patient quality of life (Figure 1).