Xenogender is defined as "a gender that cannot be contained by human understandings of gender; more concerned with crafting other methods of gender categorization and hierarchy such as those relating to animals, plants, or other creatures/things". Xenogender individuals may use ideas and identities outside of the gender binary to describe themselves and avoid binary gendered identifiers, such as using only their first name or the name of an animal. They may feel they cannot place a label on themselves, or feel as though they lack the terms to fully express their gender or identity, something that derives from a lexical gap.[note 1] The term "xenogender" itself was designed to help fill the lexical gap by using terms not typically associated with gender or describing gender with metaphors. Since it is a gender identity that is outside the binary concepts of masculinity and femininity, xenogender is a non-binary identity.
The term xenogender was proposed on June 24, 2014, by Baaphomett, a user on Tumblr. The prefix xen- or xeno- means stranger, guest, or host. The word "xenine" has been used to mean "of or pertaining to xenogenders", with "xenity" as a noun form.
Xenogender is part of the MOGAI community; MOGAI is an acronym for Marginalized Orientations, Gender Alignments, and Intersex, and serves as an alternative to LGBTQIA+ as an umbrella term for people who are not cisgender and/or heterosexual.
The annual Gender Census is an online, international survey of people who do not strictly identify with the gender binary. It had 44,583 respondents in 2021. Of those respondents, 0.8209% identified themselves specifically with the term xenogender,[note 2] while at least 3.3937% of the respondents identified with one or more xenogender identities,[note 3] including xenogender itself. The most frequent of those terms were related to gendervoid and catgender.
Multiple xenogender flags have been proposed. On DeviantArt, Roswell (under the username Pastelmemer) created two flag options on January 15, 2017. Both use the same seven stripe colors, which are described as common shades from iris flowers. The central yellow stripe symbolizes genders that have no relation to the gender binary. The symbol in the center of the designs is the astronomical sign for the asteroid 7 Iris, which is named after the deity associated with rainbows; this symbol is white in the first design and black in the other.
Another flag was created on February 17, 2017, using stripes by an anonymous user and a symbol by Mod Hermy from Pride-Flags. Its stripes are seven shades of blue-purple, and it has a central symbol in yellow and light purple that is designed to resemble an iris flower.
Xenic, also known as xeno-aligned, is similar to xenogender; however, they are not meant to be equivalent. It was proposed by Tumblr user abandonedabandoned to explain a gender alignment that is not male- or female-aligned, nor is it non-aligned. The definition of xenic or xeno-aligned is: "when your gender experience (gender, desired/current presentation, dysphoria, other expressions) doesn't fit the human binary of gender alignments. Instead of male or female aligned, one would feel like they're more aligned with animals, plants, things, and/or concepts. These terms were made with alterhumans and xenogender individuals in mind, but any nonbinary person who feels xenic fits their identity may use it."
Perceptions and discrimination
Christine Feraday, who researched Tumblr's queer identity language for her master's thesis, wrote that xenogenders are examples of what she calls "neo-identities", new words that are a reaction to rigid, cisheteronormative conceptions of identity. One of these is monstergender, which she defines as "a gender that feels monstrous in some way". Feraday suggests that neo-identities are emerging now partly as a reaction to dominant cultural ideas about what it means to be gendered and what it means to experience desire; in doing so, they threaten cisheteronormativity.
People with neo-identities may be targeted for criticism, shaming, ridicule, harassment, or accusations of being a "faker". Neo-identities are regularly criticized as being a new phenomenon created by young people looking for attention. Pejoratives like "Tumblrina", "Tumblr special snowflake", and "genderspecial" are all words to describe LGBT+ Tumblr users using uncommon identity labels to describe themselves. Feraday notes that some identity words that are now well-known (such as butch, femme, and boi) could be conceived as the "neo-identities" of an earlier time period. The experiences being described by neo-identities are not necessarily new, and these identities are also influenced by the historical and cultural context within which they emerge. 
Staying in the closet by not openly identifying as a neo-identity becomes a form of self-protection against the risks of coming out. However, not engaging in identity exploration can interrupt the process of identity formation and lead to using an inaccurate identity label that does not truly fit. The discomfort of feeling one is something "other" than the mainstream labels sometimes becomes a feeling of being "invalid" or "abnormal". Neo-identities can be life-saving and life-affirming by reassuring people that they are not "broken" or "wrong" for better relating to other words.
Because they require explanation and conversation since they are not well-known, neo-identities are in many ways considered too conspicuous. Criticisms of neo-identities can be wrapped in pretend acceptance and false concerns about "legitimate" non-cis, non-straight people, from the standpoint that people using neo-identities are undermining the legitimacy of other non-cis and non-straight people.
The online transgender community (primarily North American) and some of the offline trans community (such as in France) has been heatedly debating the inclusion of xenogender identities in trans support networks and political activism. Trans activism is largely concerned with self-determination for trans people, as well as ending state-sponsored and state-sanctioned violence against trans people. In online spaces, xenogender individuals have expressed that they do not feel included in the political discourses and support networks of non-xenogender trans rights activists. Members of the latter group have argued that people with xenogender identities are not oppressed for those identities in the same way that a non-xenogender trans person is oppressed, sometimes to a life-endangering extent, for being transgender.
In a counseling reference book related to gender diversity, its description of xenogender says that some research suggests these forms of non-binary identity may be linked to synesthesia, a condition where someone's senses are experienced as linked to each other; for example, the individual may perceive certain sounds as linked to specific colors. It is possible that non-binary people with synesthesia or synesthesia-like perceptions may experience their gender identity and describe it in terms that other people do not attribute to gender, such as time, light, shape, size, or sensory characteristics like texture or sound.
- A lexical gap is a word that does not exist in a particular language, although it could exist according to that language's rules.
- 366 out of 44,583 respondents. The manually inputted responses coded as xenogender, in descending order of uses, were: "xenogender", "xenogendered", "xenogender(s)", "xeno", "xenic/xenogender", "xénogender", "xenogender - uncommon nonbinary genders that are harder to explain", "xenogender (also: transxenine)", "xenogender (category)", "xenogender (possibly)", "xenogender (sometimes)", "xenogender femme - gender that's femininity is beyond the construct and not defined by concepts of woman", "xenogender user", "xenogender/xenic", "xenogender/xenine", "xenogender/neurogender", "xenogenderfluid", "xenogenderqueer", "xenogenders", "xénogenre".
- At least 1513 out of 44,583 respondents; data processing is currently incomplete.