Berdache. A strange word, to be sure, but one that has a long and complicated history. The Berdache tradition is a Native American/American Indian tradition that allowed for gender role change.
Gender role change is the adoption, for various reasons, of a culturally defined social role that is dictated to the opposite sex. This means that a man could adopt the social role of a woman and vice versa. In the Berdache tradition, this was almost always a permanent change. http://hubpages.com/hub/Native-American-Berdache-Tradition