Xumgender, also known as pendogender, is the state of never being satisfied with one's gender, no matter how well it fits, due to self-doubt or identity issues. This causes one to compulsively search and seek out something that fits even better—to find "the gender" or "the one truth"—though one will never be found due to: a) one's neurotype, b) the fact that words will never be able to describe one's gender, and/or c) one's gender being paradoxical. This inability to find a "one true gender" frequently causes anxiety and doubt and can even cause the xumgender label to feel imperfect to the individual.
This term is exclusive to those who are neurodivergent. It was specifically coined with anxiety disorders, OCD, and OCPD in mind. The term implagender exists for neurotypical individuals who relate to this experience and don't want to appropriate.