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.
Numerology. 1  Chaldean Numerology. The numerical value of jawn in Chaldean Numerology is: 4. 2  Pythagorean Numerology. The numerical value of jawn in Pythagorean Numerology is: 3.