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.
Jawns can mean anything as long as it is used in context. A verb, noun, pronoun, adverb, preposition, or even an exclamation. Jawns emphasizes the significance of the lack of anything else to say. Jawns originates from the word 'jawn' used in Philly.