gender bender
1. One who dresses and/or behaves in the manner or style of the opposite sex. Tom works as an accountant during the week, but he has a performance routine as a gender bender on the weekend.
2. One who challenges, denies, or explores the borders or limitations of gender identity, typically through means such as activism, transvestitism, academic discourse, etc., or a combination thereof. Some of the leading academic gender benders are gathering this week for a summit on transgender rights.