They're the too often forgotten "I" at intersex end of LGBTQI, sexi big tits according to the Intersex Society of North America1 adult every people is born with intersex body that doesn't fit what we typically think of as "male" or adult.
So, you identify as intersex. What does that mean?
Intersex Activist and Writer Hida Viloria on Being ‘Born Both’
Woman A: Being intersex means being born with some characteristics that don't neatly fit into the "normal" spectrum of human sexual development were there such a thing.
Myself, I look completely female, but happen to have XY chromosomes. I don't have an official diagnosis, and often with intersex condition, that's the case. The best I could get is gonadal dysgenesis, which is a fancy way of saying that my gonads would-be ovaries or testes in the womb never developed into anything.
I started with an XY chromosome set, but because those gonads didn't develop and produced no hormones, my body kept the Y chromosome but just didn't develop male parts.
So my body stuck along the default path of looking fully female on the outside, but having no functional female reproductive parts on the inside.