Is there a word for when a word is used as both the superset and subset?
The example comes from the word atheist (putting aside none of this is universally agreed). In this world we refer to
- Atheist, or weak atheist — does not believe in god
- Strong atheist — believes there is no god
Atheist is both the superset encompassing weak and strong atheist, but it’s also a subset in that every atheist is at a minimal level a weak atheist (but possibly a strong atheist on top of that). Many atheists will refer to themselves as just atheists, and the subset only when needed to differentiate or stress their view.
Hope that makes sense and that there is an obscure word for this.