Xynthouri is a singular gender identity, just like female, male, juxera, etc. It is a gender that is derived but distinctly separate from outhrinity and xeninity. Xynthouri is a single gender that is derived from both outhrinity and xeninity, but is a single gender, not a mix of the two, and is still completely unrelated to how xenine people and outherine people experience their (respective) xeninity and outhrinity.
Xynthouri is not a combination of outherine and xenine, nor does it describe someone who is multigender who is both outherine and xiaspec or has xenogenders. It is a distinctly separate gender from the two: derived from them but experienced as a singular, completely coalesced gender that relates heavily to qualities of outhrinity described in an entirely non-standard xenine way. That experience is core to the gender but is still separate from "standard" outhrinity and xeninity.
It's important to note that xynthouri is a gender, not a gender identity, alignment, modality, etc. Someone who is xynthouri would say "I am xynthouri" or "I am xynthourian", not "I am a xynthouri". Someone can be aligned with being xynthouri, but it is not in and of itself an alignment, as it's a complete gender, not just an alignment or quality. Since xynthouri is derived yet fully separate and distinct from outhrinity and xeninity, xynthouri people may or may not identify as outherine and/or xiaspec.
The masculine version of xynthouri is xynthvir, the feminine version of xynthouri is xynthera, and the androgynous version of xynthera is xynthari.
Moon Symbol
The symbol for xynthouri people is a group of stars because, in nature and in many cultures, stars are portrayed as being derived from gendered aspects and qualities, but are still entirely separate from the world's concepts of binary genders, and experience those connections in a way that connects the gender experience to non-standard xeninity, making stars the perfect symbol for xynthouri people.
History
The term xynthouri was coined by FANDOM user Reign of the queerios on a blog post on March 11, 2021, along with its masculine, feminine, and androgynous counterparts.