Uingender

Uingender is an umbrella term for any genders that are unknown, unnamed, undecided, unsure, undefined, unidentified, unquantifiable, unexplainable, or undetermined in nature (UIN).  It is not the same as questioning, as an uingender individual can be certain in the fact that their gender is unidentifiable or unknowable. Uingender does not have to be a temporary state, and they do not have to be looking for to understand their gender.

It can also be used as a gender on its own, when being undefined is its main feature. It's often used by individuals who cannot narrow down their gender any more than being unidentifiable.

History
It is unknown who the orginal coiner is. It is assumed that the term orginated on Imoga-Pride on tumblr by an anonymous user.

Flag
The creator of the flag is Imoga-Pride on tumblr on January 13th, 2019.