This basic glossary defines words as they are used on this site and throughout the community. Terms are in alphabetical order.

Alterhuman: An umbrella term for a wide range of communities that center around experiencing something that is alternative to humanity, or an alternative way of experiencing humanity. This includes groups such as therians, otherkin, fictionkin, otherhearted folk, those with synpaths, plural systems, soulbonders, and others. The state of being alterhuman is known as alterhumanity.

Copinglink: An identity that exists solely as a coping mechanism. Identities of this sort are often chosen, voluntary identities that are formed in order to cope with a particular issue, and are often not as ingrained and long-lasting as 'kin identities. An individual with a copinglink is known as a copinglinker.
This term falls under the Otherlink umbrella.

Fictionflicker: An experience of having a temporary fictional identity following the consumption of some kind of media. This oftentimes presents as experiencing shifts, similar behavior and thought patterns, and sometimes noemata of a fictional character or species for some time, even sometimes as long as a couple months, after watching/reading/etc something. However, this identity will fade over time without maintained interest in the media. This can be referred to as just flickering for short. An individual who fictionflickers is known as a fictionflickerer.
In science, this is known as experience-taking.

Fictionhearted: An individual who experiences a deep connection of some kind with an individual or species from a fictional source. The subject of a fictionhearted person's connection is known as a hearttype.
This term can be used interchangeably with synpath.

Fictionkin: An individual who identifies wholly or partially as an individual or species from a fictional source. The subject of a fictionkin's identity is known as a fictotype. The state of being fictionkin is known as fictionkinity.

Fictive: A member of a system (more than one consciousness or person inhabiting a body) who is a fictional character. This can range from individuals who feel as if they are the actual fictional character who was transferred into the body, to those who believe they were only modeled after a character and have their own current identity, to a variety of other beliefs for how one is related to the character they appear as.

Kin-for-fun: An individual who, while calling themselves kin, does not believe they are actually their kintypes. They see the definition of 'kin being to relate to something, or something to call oneself as a game, like roleplaying. They tend to view otherkin/fictionkin who identify as their kintypes as taking it too seriously or being delusional. They tend to refer to being kin as a verb ("to kin" or "kinning"), being unaware that to be 'kin is not an action that is intentionally taken.
Importantly, this does not refer to people who genuinely identify as their kintypes, but also have fun with their identities.
This term is often abbreviated as KFF.

Noemata: A term for knowledge one has of their kintype, such as, for example, whether their fur was brown or white, or if they lived in the ocean. This term is distinct from the experience of memories, but can co-occur with them.

Otherhearted: An individual who experiences a deep connection of some kind with a nonhuman species. The subject of an otherhearted person's connection is known as a hearttype.
This term is sometimes used as an umbrella for all types of 'hearted identities.

Otherkin: An individual who identifies wholly or partially as nonhuman. The subject of an otherkin's identity is known as a kintype. The state of being otherkin is known as otherkinity.
Otherkin is often used an an umbrella term to include therians, otherkin, and fictionkin, but its community has its own origins in the 1970s.

Otherlink: An identity that is intentionally and consciously formed for any reason. This encompasses nonhuman, fictional, and other related voluntary identities. An individual with an otherlink is known as an otherlinker.
For a more specific type of otherlinking, see Copinglink.

Synpath: Something that someone has a connection with, relates to, acts like, or otherwise resonates with. There is no word for a person with a synpath; a synpath is the subject of the connection.
This term can be used interchangeably with otherhearted and fictionhearted.

Therian: An individual who identities wholly or partially as a nonhuman animal. The subject of a therian's identity is known as a theriotype. The state of being a therian is known as therianthropy.
The community emerged independently from otherkin in the early 1990s.