Since the beginning of the last century, clinical observers have described the propensity of certain males to be erotically aroused by the thought or image of themselves as women. Because there was no specific term to denote this phenomenon, clinicians' references to it were generally oblique or periphrastic. The closest available word was transvestism. The definition of transvestism accepted by the end of the twentieth century, however, did not just fail to capture the wide range of erotically arousing cross-gender behaviors and fantasies in which women's garments per seplay a small role or none at all; it actually directed attention away from them. The absence of an adequate terminology became acute in the writer's research on the taxonomy of gender identity disorders in biological males. This had suggested that heterosexual, asexual, and bisexual transsexuals are more similar to each other-and to transvestites-than any of them is to the homosexual type, and that the common feature in transvestites and the three types of non-homosexual transsexuals is a history of erotic arousal in association with the thought or image of themselves as women. At the same time, the writer was becoming aware of male patients who are sexually aroused only by the idea of having a woman's body and not at all by the idea of wearing women's clothes. To fill this terminological and conceptual gap, the writer introduced the term autogynephilia(love of oneself as a woman).