Well a transexual can be a person under going sex reasignment surgury.

It can means a man with breast of a woman but has not quite reached the point of no return ie the big snip.

But although allot rarer It can also be a Woman going to be a man ie the big pop... and plug...

This is different than a crossdresser where a man like's to wear womans clothing and pass as a Woman.

Hope this clears it up if I missed anyting just ask