Metagender

Metagender is a gender modality for being neither transgender nor cisgender. Similar to isogender and absgender. It's also a gender identity for identifying around a gender aesthetically or emotionally, where your gender identity is almost that gender, but not quite, and also extends beyond that. It is most commonly used by non-binary people or genderfluid people.

Flag
The Metagender flag was made by Tumblr user gendies 'n' more. They gave it no defined meaning.