From the Diagnostic and Statistical Manual of Mental Disorders, version IV:
"The paraphilic focus on Fetishism involves the use of nonliving objects (the "fetish"). Among the more common fetish objects are women's underpants, bras, stockings, shoes, boots, or other wearing apparel. The person with Fetishism frequently masturbates while holding, rubbing, or smelling the fetish object or may ask the sexual partner to wear the object during their sexual encounters. Usually the fetish is required or strongly preferred for sexual excitement, and in its absence there may be erectile dysfunction in males. This Paraphilia is not diagnosed when the fetishes are limited to articles of female clothing used in cross-dressing, as in Transvestite Fetishism, or when the object is genitally stimulating because it has been designed for that purpose (e.g. a vibrator). Usually the Paraphilia begins by adolescence, although the fetish may have been endowed with special significance during childhood. Once established, Fetishism tends to be chronic."
The underlined parts are the important parts. A fetishist is a person who cannot or has significant difficulty getting aroused without the presence of the nonliving object. Cross-dressing is not considered a fetish by the psychological community. ^_^
