The condition of being neither male nor female, but something in between. Often refers to an infant with "ambiguous" genitalia. Intersexed conditions include Androgen Insensitivity Syndrome, Klinefelter's Syndrome, vaginal agenesis, ovotestes, and anyone who is not XX or XY. Estimated to be between 1% and 0.01% of the population.
Many FtMs claim to have been born intersexed, but usually it's bullshit: they're just traumatized by the idea that they were born female.