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.
Intron. Definition. noun, plural: introns. (molecular biology) A noncoding, intervening sequence of DNA within a gene that is transcribed into mRNA but is removed from the primary gene transcript and rapidly degraded during maturation of the RNA product. Supplement. An intron is a nucleotide sequence within a gene.