(Namespace: plural glossary)
| Type of term | Possible type of headmate |
|---|---|
| Synonyms or near-synonyms | Headmate, facet, fragment, insider, part, self |
| Antonyms or near-antonyms | Body, core, host, introject, original |
Some systems refer to their headmates as alters. The connotation is usually that the headmate in question is a self or self-like, as opposed to an introject, but is still not the definitive self, if the system is of the sort to have such a member.
The word “alter” is somewhat specific to headmates in disordered systems, e.g. DID or OSDD. (Even people with OSDD are sometimes hesitant to use this word, believing it's exclusive to people with DID specifically.) Disordered systems may experience non-disordered systems' use of the word as appropriation, and non-disordered systems who do not use the word for themselves may experience it as stigmatizing when applied to them by others.