Mesogender is a gender that is something between male and female but not distinct from both.[1][2] This can include bigender, centrigender, cogender, and any other similar genders.
History
Mesogender was coined by Tumblr user malcubus on July 14th, 2019.
Flag
The mesogender flag was coined by Tumblr user gendies 'n' more on January 10th, 2019. It has no confirmed meaning.