Abinary (abbreviated AB) refers to any gender that is completely unrelated to maleness, masculinity, femaleness, or femininity, and is nowhere in between those things, while not necessarily being genderless (although agender people may also identify as abinary). An abinary person may feel a strong sense of gender, however that gender is completely unrelated from the binary genders.
Abinary is sometimes used as interchangibly with "unaligned non-binary" or "neutral aligned non-binary". It refers to the fact that some non-binary people are "man-aligned" or "woman-aligned" while not being men or women. Abinary/unaligned non-binary people are completely separate from these categories.
The term abinary is combination of the prefix "a" and "binary", to mean "lacking binary". Its first mention was in the midbinary coining post by nothorses (previously starmashine) on or before October 25, 2016. Other similar words popped up such as exterbinary and off-binary.
The abinary flag was created by arco-pluris through the Tumblr blog beyond-mogai-pride-flags on May 18, 2018. There is no known meaning, however yellow is commonly used as an abinary color due to being unrelated to the colors of the binary genders (blue and pink).
Two alternate flags were created by Clear.Skyes on or before December 15, 2020. They have no confirmed meaning.