Thesaurus ⁽⁰⁾

A thesaurus is a type of vocabulary in which concepts are related to each other as either exact matches or related alternatives. A thesaurus (in information terms) is a variation on a vocabulary, designed to reflect areas where additional complexity is required beyond a hierarchical arrangement. This might include related terms, synonyms and preferred/deprecated terms. Thesauri are commonly used for content classification and for providing synonyms in content indexing.