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.
Etymology[edit] Reduplication of jaw. jaw-jaw â(third-person singular simple present jaw-jaws, present participle jaw-jawing, simple past and past participle jaw-jawed) (slang) To talk at length; to chatter or jabber.