Antigender

Not to be confused with Anti-Gender Movement.

The antigender flag.

Antigender is an umbrella term for any gender that can only be described as being the opposite of another gender. For example, antiboy would be the opposite of a male. However, antiboy would not necessarily be female, because male and female are not opposites. Antigender may also be used by people who cannot narrow down their gender, but know they are definitely not a certain gender.