Sentence:  One head of a small gay charity visibly flinched when I mentioned my boyfriend and has been cold towards me ever since. I've even caught someone staring down my top to see if I'm <WSD>transgender</WSD>. 
Meaning of the word marked with <WSD> tags:  Having a gender (identity) which is different from the sex one was assigned at birth: being assigned male at birth but having a female or non-binary gender or vice versa; or, pertaining to such people. (Compare "transsexual", and the following sense.)