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.
Definition of AWN. : one of the slender bristles that terminate the glumes of the spikelet in some cereal and other grasses. â awned \ËoÌnd\ adjective. â awnÂ·less \ËoÌn-lÉs\ adjective.