Achiralgender

Achiralgender is an eugender without an antigender or an ungender, or vice-versa due to an impossibility of the reverse form. It's a gender that cannot possess a polar opposite.

History
The term achiralgender was first coined by Tumblr user mogai-ringo on September 5th, 2018 in order to describe their experience.

Flag
The achiralgender flag was coined by a user going by Amnisty on November 17th, 2020. The gold represent the lone genders that achiralgender encompasses, the black represents the lack of an antigender, and the white represents multigenders that inherently have no opposite, such as pangender, since pangender encompasses agender as well, making no opposite for it.

Etymology
The term achiralgender was taken from achiral, a molecule that cannot be superposed on its mirror image by any combination of rotations and translations.