I can't believe it's late 2010 and this word hasn't been defined here yet.
Anyway, a
transwoman is a male-born human who followed their heart and soul and left the company of the men to become one of the ladies. This takes quite a bit of confidence to do and they typically complete name changes and recieve hormonal treatments (
HRT), hair removal treatments, plastic surgery, and the fabled SRS (Sex Reassignment Surgery, or
sex change) to do this. The ability to pass in society as a woman on a regular basis does vary amongst
transwomen due to physical, psychological, and situational differences. Either way though, transwomen, so long as they're not just crazed men who'll regret everything later, are, always were, and always will be women.
Some examples of famous transwomen include Israeli Pop Singer Dana International and Christine
Jorgenson, the transwoman that always seems to appear in High School History Textbooks.