Aa transgender person who was assigned male at birth but whose gender identity is that of a woman. 
Some trans women who feel that their gender transition is complete prefer to be called simply women, considering trans woman or male-to-female transsexual to be terms that should only be used for people who are not fully transitioned. A trans woman with XY written on her hand, at a protest in Paris, October 1, 2005. A transwoman (sometimes spelled as trans-woman or trans woman) is a male-to-female (MTF) transsexual or transgender person. Many people in this group like the name trans woman over the many medical terms that are out there. Other non-medical names are t-girl, tg-girl and ts-girl. Transgender, though, is the more common name. A trans woman (sometimes trans-woman or transwoman) is a transgender person who was assigned male at birth but whose gender identity is that of a woman. The label of transgender woman is not always interchangeable with that of transsexual woman, although the two labels are often used in this way. By Tom Head. Definition: A transwoman, shorthand for  transsexual woman , is a woman who was assigned a male gender that is not consistent with her sense of self, and who lives and identifies as female.
https://en.wikipedia.org/wiki/Trans_woman https://simple.wikipedia.org/wiki/Transwoman https://en.wikipedia.org/wiki/Trans_woman http://civilliberty.about.com/od/gendersexuality/g/Transwoman-Transsexual-Woman.htm
what is a trans woman