Non-cisgender; an umbrella term encompassing transgender, transsexual, and often also genderqueer/nonbinary, genderfluid, third-gender, etc. — all gender identities other than cisgender.
Having changed, or being in the process of changing, physical sex (because it does not match desired sex) by undergoing medical treatment such as hormone replacement therapy (HRT) and optionally sex reassignment surgery (SRS), or rarely only SRS.
A transsexual person.