A multigender where someone who is partially (a) nonbinary gender(s) and part gendernull or both at the same time.
The xenogender equivalent is Xenull, the neutral equivalent is Neutranull, and the androgynous equivalent is Androgynull. The fluid equivalent is Nullenbyfluid.
History
The term Nullenby was coined by tumblr user nonbiarrow on 09/05/2021, as well as its flag.
Flag
The flag shows three stripes: grey for gendernull, yellow for nonbinary gender and light yellow for being inbetween or both/all genders at the same time.