Ontology may have been the right word, but the wrong article was linked:

https://en.m.wikipedia.org/wiki/Ontology_(information_scienc...

My feel for the words is that any ontology which uses a tree to organize its names and defines no relationships between those objects is a taxonomy, but some ontologies do more.

I'm leaning towards ontology here because inferior and superior are not presented as mere subtaxa of the genus "ferior", but as opposites. I don't think taxonomy does opposites.

Knowledge Organization System (KOS) is also a synonym.