Thesaurus (information retrieval)
In the context of information retrieval, a thesaurus (plural: "thesauri") is a form of controlled vocabulary that seeks to dictate semantic manifestations of metadata in the indexing of content objects. A thesaurus serves to minimise semantic ambiguity by ensuring uniformity and consistency in the storage and retrieval of the manifestations of content objects.
Source: Wikipedia — Thesaurus (information retrieval) (CC BY-SA 4.0)