An autogynephile is a transwoman who is sexually attracted to their own body as female. ("Auto" means "self," "gyne" means "woman," and "phile" means "lover.")
Researcher Ray Blanchard infamously invented/discovered this category and theorized that any transwoman who is not attracted to men (whether gynephilic, bisexual, or asexual) is an autogynephile and their transitioning is of purely sexual motivation. This view is rejected by the trans community and neither accepted nor rejected by the medical community.
An article I like about autogynephilia