I consider transsexual outdated and I use transgender myself even though I am on hormones and am wanting SRS. Transsexual was/is used for anyone who has taken any steps to modify their body including hormones so it's not exclusive to surgery.

Now to get onto why I consider transsexual outdated and wrong.

Trans is actually used as the opposite of cis in the same way it's used in chemistry like cis/trans isomerism and cis/trans fat so trans isn't short for transition it's meant as a descriptor to mean the opposite of cis. It goes into why I think transsexual is outdated, It was originally used for anyone who was trans regardless of whether they were making any changes to their body or not, as transgender became popular it started meaning those who are changing their body. Transsexual doesn't mean "transitioning to another sex" this is it;s definition;

"Transsexual people experience a gender identity inconsistent or not culturally associated with their assigned sex, i.e. in which a person's assigned sex at birth conflicts with their psychological gender".

Which is pretty much the same as transgender. Other problems also include cissexual not existing, the definition would also be "the opposite sexual attraction/physical sex" so cisexual and transsexual would actually be more accurate for homosexual and heterosexual due to the "sexual" meaning and cis/trans meaning the opposite of each other, it is confused with sexuality since it shares the name sexual with homosexual and bisexual when in fact it's gender not sexuality.

Transsexual meaning "to change/transition" was only used in the medical diagnosis of transsexualism which was required and still is for those countries using the IDC-10 and not the DSM (which replaced it with gender dysphoria) to medically transition.