thesaurus

16th century, from Latin thēsaurus, from Ancient Greek θησαυρός (thēsaurós, “storehouse, treasure”); its current English usage/meaning was established soon after the publication of Peter Roget's Thesaurus of English Words and Phrases in 1852. Doublet of treasure.

• IPA^(key): /θɪˈsɔːɹəs/

• Audio (Southern England):

  (file)

• Rhymes: -ɔːɹəs

thesaurus (plural thesauri or thesauruses)

2. A publication, traditionally in the form of a printed book and now often online, that provides synonyms (and sometimes antonyms and other semantic relations) for the words of a given language.

   Synonym: synonymicon

   "Roget" is the leading brand name for a print English thesaurus that lists words under general concepts rather than just close synonyms.

   • 2008 April 18, Charles Mcgrath, “The Keeper (See: Steward, Caretaker) of Synonyms”, in New York Times‎^[1]:

     As reference books go, the thesaurus has had a somewhat checkered history, in fact, and has probably occasioned as much bad writing as good.

4. (archaic) A dictionary or encyclopedia.
6. (information science) A hierarchy of subject headings: canonical titles of themes and topics, the titles serving as search keys.

   Coordinate terms: catalogue, controlled vocabulary, index

• ontology
• Wiktionary's thesaurus
• Appendix:Roget's thesaurus classification
• Appendix:Roget MICRA thesaurus
• Appendix:Moby Thesaurus II

• “thesaurus”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• “thesaurus”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC.
• OneLook Thesaurus in OneLook, 2023

• thensaurus (pre-Classical)
• tēsaurus, tēsōrus (Low Latin)

From Ancient Greek θησαυρός (thēsaurós, “storehouse, treasure”).

• (Classical Latin) IPA^(key): /tʰeːˈsau̯.rus/, [t̪ʰeːˈs̠äu̯rʊs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /teˈsau̯.rus/, [t̪eˈs̬äːu̯rus]

thēsaurus m (genitive thēsaurī); second declension

1. treasure, hoard
   • Late 4th century, Jerome [et al.], transl., edited by Roger Gryson, Biblia Sacra: Iuxta Vulgatam Versionem (Vulgate), 5th edition, Stuttgart: Deutsche Bibelgesellschaft, published 2007, →ISBN, Danihelis 1:2:

     […] et vasa intulit in domum thesauri dei sui

     " […] and he brought the vessels into the treasure house of his god."

2. a dear friend, loved one
3. a vault for treasure
4. chest, strongbox
5. repository, collection

Second-declension noun.

• thēsaurārius
• thēsaurensis
• thēsaurizātor
• thēsaurizō

• “thesaurus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “thesaurus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• thesaurus in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• thesaurus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• “thesaurus”, in Harry Thurston Peck, editor (1898), Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
• “thesaurus”, in William Smith et al., editor (1890), A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin

Unadapted borrowing from Latin thesaurus.

thesaurus m (plural thesauri or thesaurus)

1. Alternative form of tesauro