Atriboy, atrinboy, or atrinaboy, refers to an atrinary boy, this is also abiatrinary.
As the definition of atrinary states, it is referring to any genders that are completely unrelated to maleness, masculinity, femaleness, femininity, neutrois-ness, or neutrality, and is nowhere in between those things, while not necessarily feeling genderless.
The gendered part of themselves is being a boy. Someone who is a atriboy may feel as if they're a boy while not being related to maleness, masculinity, femaleness, femininity, neutrois-ness, or neutrality, and feels as if they're nowhere in between any of them.
This could be due to feeling a connection to boyhood rather than maleness, inherently. A atriboy may feel as if they're a boy while also not being a part of the gender trinary.
History
The term was coined by Reddit user u/hiitsyaz in August 2021, with no exact date.
Atriboy was coined due to wanting to show how differently one can experience their gender(s), due to how (stereotypically) masculinity is associated with being a boy. This isn't the case though, as one can present however one wants to, regardless of their gender(s).
Etymology
The name combines the terms atrinary and boy.