In a trans context, a cross dresser is a male who dresses as a woman or girl but does not identify as transexual. The line can blur between a transexual and a cross dresser but generally a transexual identifies as a woman completely and permanently and a cross dresser identifies as a woman only while cross dressing, only partially, or not at all. A transexual will not identify as cross dressing because they feel feminine clothes are appropriate for their gender and are not crossing the gender line. Female cross dressers exist but are rare. The term "transvestite" was once a synonym for cross dresser but is rejected for its stigma.
Trans & Gender 101 >