(1) a mental disorder in children, adolescents, or adults characterized by a strong and enduring cross-gender identification that manifests in insistence that one is, or desires to be, the other sex; this disorder involves persistent discomfort with one's assigned sex or the gender role of one's sex, such that there is clinically significant distress or impairment in functioning, often leading to adopting to various degrees the gender role of the other sex. (2) a DSM diagnosis that is established when the specific criteria are met.transsexualism.
