transsexual

First recorded in 1955–60; trans- + sexual, originally in transsexualism (coined in 1953)

The vocabulary around transsexualism originated in medical study of human sexuality. In the 1980s, transsexualism was listed as a mental illness in the manuals of the American Psychological Association and the World Health Organization. Transsexual and transsexualism are no longer used in the medical or psychological professions, having been replaced by gender dysphoria in medical terminology.
Today, the transsexual identity is perceived to fall under the wider umbrella term trans, though it is not exactly equivalent to the term transgender. Transsexual is still sometimes the preferred term among older trans people who have been using the term transsexual to describe their own identity for years. However, owing to the previous association of transsexual with a mental disorder diagnosis, and a history of disparaging use in popular culture, the term is now often considered offensive in general use, especially among younger speakers. There is also some tension between the terms transsexual and transgender, the former term associated with external and physical markers of gender identity, and the latter with internal identification along a gender continuum. Still other speakers use the two terms interchangeably. As always when using identity labels, the best choice is the one with which the person in question self-identifies. See also transgender.