This term was coined by wulgendeur on tumblr, and is intended for use as an adjective. For example one would say "I'm Proxvir" but not "I'm a Proxvir".
Someone who is Proxvir may also identify with the term, ''Thirdgender'' due to the fact that this gender is on a plane not connected to the gender binary. It is a whole, single gender, that is masculine. This is not to be confused with demi-boy, because demi-boys tend to have some connection to the binary gender male. Anyone of any gender expression can be Proxvir, even the most femenine of individuals.
''I personally feel that my gender is Proxvir, because I am androgynous, masc leaning, expression wise. However my gender was a different story. I couldn't find any word other than Aporagender to describe my gender. It was still a masculine gender, but I knew I wasn't a male. Being called a man or a he gives me dysphoria just as bad as she does. I identified with Thirdgender before I found Proxvir. This gender identity is real, because I am real.'' -NonbinarySushiRoll, USA, 17.