Transgender is an adjective to describe a person whose gender identity does not confirm to the sex which they were assigned at birth. A transgender person may or may not experience social and/or bodily dysphoria or unease and may or may not desire to change their bodies through gender confirming surgeries and/or HRT (Hormone Replacement Therapy). Changing your body is not a criterion to be trans-identified and neither is your gender expression - since gender identity and gender expression can be separate.