What is "thesaurus"

Thesaurus \The*sau"rus\, n.; pl. Thesauri. [L. See Treasure.] A treasury or storehouse; hence, a repository, especially of knowledge; -- often applied to a comprehensive work, like a dictionary or cyclopedia.

1823, "treasury, storehouse," from Latin thesaurus "treasury, a hoard, a treasure, something laid up," figuratively "repository, collection," from Greek thesauros "a treasure, treasury, storehouse, chest," from root of tithenai "to put, to place" (see theme). The meaning "encyclopedia filled with information" is from 1840, but existed earlier as thesaurarie (1590s), used as a title by early dictionary compilers, on the notion of thesaurus verborum "a treasury of words." Meaning "collection of words arranged according to sense" is first attested 1852 in Roget's title. Thesaurer is attested in Middle English for "treasurer" and thesaur "treasure" was in use 15c.-16c.

n. 1 A publication, usually in the form of a book, that provides synonyms (and sometimes antonyms) for the words of a given language. 2 (context archaic English) A dictionary or encyclopedia. 3 (context information science English) A hierarchy of subject headings—canonic titles of themes and topics, the titles serving as search keys.

1. n. a book containing a classified list of synonyms [syn: synonym finder]

2. [also: thesauri (pl)]

In general usage, a thesaurus is a reference work that lists words grouped together according to similarity of meaning (containing synonyms and sometimes antonyms), in contrast to a dictionary, which provides definitions for words, and generally lists them in alphabetical order. The main purpose of such reference works is to help the user "to find the word, or words, by which [an] idea may be most fitly and aptly expressed" – to quote Peter Mark Roget, architect of the best known thesaurus in the English language.

Although including synonyms, a thesaurus should not be taken as a complete list of all the synonyms for a particular word. The entries are also designed for drawing distinctions between similar words and assisting in choosing exactly the right word. Unlike a dictionary, a thesaurus entry does not give the definition of words.

In library science and information science, thesauri have been widely used to specify domain models. Recently, thesauri have been implemented with Simple Knowledge Organization System (SKOS).

Thesaurus is an album by American composer/arranger/pianist Clare Fischer, recorded and released in 1969 by Atlantic Records. Reissued in 1979 as '' 'Twas Only Yesterday'' by Discovery Records, and on CD, again by DIscovery, in 1988 as part of a CD entitled Waltz, encompassing both Thesaurus and the 1980 LP, Duality. In 2000, Thesaurus received a dedicated CD reissue under its original title from Koch Records.

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. ANSI/NISO Z39.19-2005 defines a content object as "any item that is to be described for inclusion in an information retrieval system, website, or other source of information". The thesaurus aids the assignment of preferred terms to convey semantic metadata associated with the content object.

A thesaurus serves to guide both an indexer and a searcher in selecting the same preferred term or combination of preferred terms to represent a given subject. ISO 25964, the international standard for information retrieval thesauri, defines a thesaurus as a “controlled and structured vocabulary in which concepts are represented by terms, organized so that relationships between concepts are made explicit, and preferred terms are accompanied by lead-in entries for synonyms or quasi-synonyms.”

A thesaurus is composed by at least three elements: 1-a list of words (or terms), 2-the relationship amongst the words (or terms), indicated by their hierarchical relative position (e.g. parent/broader term; child/narrower term, synonym, etc.), 3-a set of rules on how to use the thesaurus.