median - in reference to plurality, a system where members are less distinct from each other compared to a those in a multiple system [1] [2]. Considered somewhere between multiple and singlet.
medusan - an orientation label denoting those who are sexually and/or romantically attracted to other alterhumans or nonhumans; particularly those who identify as intelligent nonhuman creatures including monsters, aliens, or mythical creatures [3]. This label is intended for use by those who identify as alterhuman or nonhuman.
mixed system - in reference to plurality, a system containing a mix of median and multiple members [4].
multiple - in reference to plurality, a group of distinct individuals inhabiting a single body, in which more than one person can take control of the physical body [5]. On the opposite end of the spectrum as singlets.
multiverse theory - the theory that there are many alternate universes in existence in addition to our own [6] [7]. This theory is often used as a possible explanation as to why fictionkin and mythical otherkin exist (they ended up in the wrong universe) [8], why fictionkin doubles exist (doubles are from separate but similar universes), and why some doubles have different memories of what was canon in their lives.
mythling - a facet identity that falls somewhere between fictive/factive and endel/delusional attachment identities [9]. This term is intended exclusively for those who experience delusions.