A thesaurus (plural thesauri or thesauruses) or synonym dictionary is a reference work for finding synonyms and sometimes antonyms of words. They are often used by writers to help find the best word to express an idea:
...to find the word, or words, by which [an] idea may be most fitly and aptly expressed
Most thesauri do not include definitions, but many dictionaries include listings of synonyms.
Some thesauri and dictionary synonym notes characterize the distinctions between similar words, with notes on their "connotations and varying shades of meaning". Some synonym dictionaries are primarily concerned with differentiating synonyms by meaning and usage. Usage manuals such as Fowler’s A Dictionary of Modern English Usage often prescribe appropriate usage of synonyms.
Thesauri are sometimes used to avoid repetition of words, leading to elegant variation, which is often criticized by usage manuals: "writers sometimes use them not just to vary their vocabularies but to dress them up too much".
Until the 19th century, a thesaurus was any dictionary or encyclopedia, as in the Thesaurus Linguae Latinae (Dictionary of the Latin Language, 1532), and the Thesaurus Linguae Graecae (Dictionary of the Greek Language, 1572). It was Roget who introduced the meaning "collection of words arranged according to sense", in 1852.
Some early synonym dictionaries include:
- John Wilkins, An Essay Towards a Real Character, and a Philosophical Language and Alphabetical Dictionary (1668) are a "regular enumeration and description of all those things and notions to which names are to be assigned". They are not explicitly synonym dictionaries — in fact, they do not even use the word "synonym" — but they do group synonyms together.
- Gabriel Girard, La Justesse de la langue françoise, ou les différentes significations des mots qui passent pour synonymes (1718)
- John Trusler, The Difference between Words esteemed Synonyms, in the English Language; and the proper choice of them determined (1766)
- Hester Lynch Piozzi, British Synonymy (1794)
- James Leslie, Dictionary of the Synonymous Words and Technical Terms in the English Language (1806)
- George Crabb, English Synonyms Explained (1818)
Roget's Thesaurus, first compiled in 1805 by Peter Mark Roget, and published in 1852, follows John Wilkins' semantic arrangement of 1668. Unlike earlier synonym dictionaries, it does not include definitions or aim to help the user to choose among synonyms. It has been continuously in print since 1852, and remains widely used across the English-speaking world. Roget described his thesaurus in the foreword to the first edition:
It is now nearly fifty years since I first projected a system of verbal classification similar to that on which the present work is founded. Conceiving that such a compilation might help to supply my own deficiencies, I had, in the year 1805, completed a classed catalogue of words on a small scale, but on the same principle, and nearly in the same form, as the Thesaurus now published.
Roget's original thesaurus was organized into 1000 conceptual Heads (e.g., 806 Debt) organized into a four-level taxonomy. For example, liability was classed under V.ii.iv: Class five, Volition: the exercise of the will; Division Two: Social volition; Section 4: Possessive Relations; Subsection 4: Monetary relations. Each head includes direct synonyms: Debt, obligation, liability, ...; related concepts: interest, usance, usury; related persons: debtor, debitor, ... defaulter (808); verbs: to be in debt, to owe, ... see Borrow (788); phrases: to run up a bill or score, ...; and adjectives: in debt, indebted, owing, .... Numbers in parentheses are cross-references to other Heads.
The book starts with a Tabular Synopsis of Categories laying out the hierarchy, then the main body of the thesaurus listed by Head, and then an alphabetical index listing the different Heads under which a word may be found: Liable, subject to, 177; debt, 806; duty, 926.
Some recent versions have kept the same organization, though often with more detail under each Head. Others have made modest changes such as eliminating the four-level taxonomy and adding new heads: one has 1075 Heads in fifteen Classes.
Some non-English thesauri have also adopted this model.
Other thesauri and synonym dictionaries are organized alphabetically.
A third system interfiles words and conceptual headings. Francis March's Thesaurus Dictionary gives for liability: CONTINGENCY, CREDIT–DEBT, DUTY–DERELICTION, LIBERTY–SUBJECTION, MONEY, each of which is a conceptual heading. The CREDIT—DEBT article has multiple subheadings, including Nouns of Agent, Verbs, Verbal Expressions, etc. Under each are listed synonyms with brief definitions, e.g. "Credit. Transference of property on promise of future payment." The conceptual headings are not organized into a taxonomy.
Benjamin Lafaye's Synonymes français (1841) is organized around morphologically related families of synonyms (e.g. logis, logement), and his Dictionnaire des synonymes de la langue française (1858) is mostly alphabetical, but also includes a section on morphologically related synonyms, which is organized by prefix, suffix, or construction.
Some include short definitions.
Some give illustrative phrases.
Some include lists of objects by category, e.g. breeds of dogs.
The Historical Thesaurus of English (2009) is organized taxonomically, and includes the date when each word came to have a given meaning. It has the novel and unique goal of "charting the semantic development of the huge and varied vocabulary of English".
Bilingual synonym dictionaries are designed for language learners. One such dictionary gives various French words listed alphabetically, with an English translation and an example of use. Another one is organized taxonomically with examples, translations, and some usage notes.
Information science and natural language processing
- W.E. Collinson, "Comparative Synonymics: Some Principles and Illustrations", Transactions of the Philological Society 38:1:54-77, November 1939, doi:10.1111/j.1467-968X.1939.tb00202.x
- Gerda Hassler, "Lafaye's Dictionnaire des synonymes in the History of Semantics" in Sheli Embleton, John E. Joseph, Hans-Josef Hiederehe, The Emergence of the Modern Language Sciences, John Benjamins 1999, ISBN 1556197594, p. 1:27-40
- Werner Hüllen, "Roget's Thesaurus, deconstructed" in Historical Dictionaries and Historical Dictionary Research, papers from the International Conference on Historical Lexicography and Lexicology, University of Leicester, 2002, Max Niemeyer Verlag 2004, ISBN 3484391235, p. 83-94
- Werner Hüllen, A history of Roget's thesaurus : origins, development, and design, Oxford University Press 2004, ISBN 0199254729
- Werner Hüllen, Networks and Knowledge in Roget's Thesaurus, Oxford, January 2009, doi:10.1093/acprof:oso/9780199553235.001.0001, ISBN 0199553238
- Gertrude E. Noyes, "The Beginnings of the Study of Synonyms in England", Publications of the Modern Language Association of America (PMLA) 66:6:951-970 (December 1951) doi:10.2307/460151 JSTOR 460151
- Eric Stanley, "Polysemy and Synonymy and how these Concepts were Understood from the Eighteenth Century onwards in Treatises, and Applied in Dictionaries of English" in Historical Dictionaries and Historical Dictionary Research, papers from the International Conference on Historical Lexicography and Lexicology, University of Leicester, 2002, Max Niemeyer Verlag 2004, ISBN 3484391235, p. 157-184
- Roget, Peter. 1852. Thesaurus of English Language Words and Phrases.
- American Heritage Dictionary of the English Language, 5th edition, Houghton Mifflin Harcourt 2011, ISBN 9780547041018, p. xxvii
- Edwin L. Battistella, "Beware the thesaurus", OUPblog, "Oxford University Press's Academic Insights for the Thinking World", February 11, 2018
- "thesaurus". Online Etymology Dictionary.
- R. S. P. Beekes, Etymological Dictionary of Greek, Brill, 2009, p. 548.
- B. Lafaye, Dictionnaire des synonymes de la langue française, Hachette 1869, 3rd edition
- John Wilkins, An Essay Towards a Real Character, and a Philosophical Language, London 1668 full text
- John Wilkins, William Lloyd (anonymously), An Alphabetical Dictionary Wherein all English Words According to their Various Significations, Are either referred to their Places in the Philosophical Tables, Or explained by such Words as are in those Tables, London 1668 full text
- Natascia Leonardi, "An Analysis of a Seventeenth Century Conceptual Dictionary with an Alphabetical List of Entries and a Network Definition Structure: John Wilkins' and William Lloyd's An Alphabetical Dictionary (1668)" in Historical Dictionaries and Historical Dictionary Research, papers from the International Conference on Historical Lexicography and Lexicology, University of Leicester, 2002, Max Niemeyer Verlag 2004, ISBN 3484391235, p. 39-52
- Gabriel Girard, La Justesse de la langue françoise, ou les différentes significations des mots qui passent pour synonymes, Paris 1718, full text
- John Trusler (anonymously), The Difference between Words esteemed Synonyms, in the English Language; and the proper choice of them determined, London, 1766 full text
- Hester Lynch Piozzi, British Synonymy; or, an Attempt Regulating the Choice of Words in Familiar Conversation, Dublin 1794 full text
- James Leslie, Dictionary of the Synonymous Words and Technical Terms in the English Language, Edinburgh, 1806 full text
- George Crabb, English Synonyms Explained, in Alphabetical Order with Copious Illustrations and Examples Drawn from the Best Writers, 2nd edition, London 1818 full text
- "Introduction - Oxford Scholarship". oxfordscholarship.com. doi:10.1093/acprof:oso/9780199254729.001.0001/acprof-9780199254729-chapter-1. Retrieved 26 March 2018.
- Lloyd 1982, p. xix[full citation needed]
- Peter Mark Roget, Thesaurus of English words and phrases, classified so as to facilitate the expression of ideas, 1853, V.ii.iv, p. 204
- Roget, op.cit. p. xxvi
- Roget, op.cit. p. 349
- e.g., George Davidson, ed., Thesaurus of English words and phrases (150th Anniversary Edition), Penguin, 2002, ISBN 0141004428, p. 454
- Barbara Ann Kipfer, ed., Roget's International Thesaurus, 7th edition, Collins Reference, 2010, ISBN 9780061715228
- Daniel Péchoin, Thésaurus Larousse, Larousse 1991, ISBN 9782033201074
- Longman Synonym Dictionary, Rodale Press and Longman Group, 1986, ISBN 0582893224
- Charlton Laird, Michael Agnes, eds., Webster's New World Roget's A-Z Thesaurus, Macmillan USA, 3rd edition, 1971, ISBN 0028632818
- Christine A. Lindberg, The Oxford American Thesaurus of Current English, Oxford University Press, 1999, ISBN 0195133757
- Oxford Thesaurus of English, 3rd edition, 2009, ISBN 9780199560813
- Merriam-Webster's Dictionary of Synonyms : Choose Words with Precision, 1994, ISBN 0877799067 uses an asterisk
- Henri Bertaud du Chazaud, Dictionnaire de synonyms et contraires, Le Robert "Les Usuels", 1998, ISBN 2850364568
- Roger Boussinot, Dictionnaire des synonymes, analogies et antonymes, Bordas 1981, ISBN 2040120092
- Francis Andrew March, Francis A. March, Jr., March's Thesaurus and Dictionary of the English Language (issued under the editorial supervision of Norman Cousins), Doubleday, 1968, p. 598 full text, 1906 edition
- Pierre Benjamin Lafaye, Synonymes français, Paris 1841 full text
- Henri Bénac, Dictionnaire des synonymes, Hachette 1956, ISBN 2010112199 (1982 edition)
- Christian Kay, Jane Roberts, Michael Samuels, Irené Wotherspoon, Historical Thesaurus of the Oxford English Dictionary, Oxford University Press 2009, ISBN 9780199208999, p. ix
- R.E. Batchelor, M.H. Offord, Using French Synonyms, Cambridge University Press, 1993, ISBN 0521372771
- Marie-Noëlle Lamy, The Cambridge French-English Thesaurus, Cambridge University Press, 1998, ISBN 0521563488
- Miles, Alistair; Bechhofer, Sean (2009). "SKOS simple knowledge organization system reference". W3C recommendation. 18: W3C.
- Yarowsky, David. "Word-sense disambiguation using statistical models of Roget's categories trained on large corpora." Proceedings of the 14th conference on Computational linguistics-Volume 2. Association for Computational Linguistics, 1992.
- Siddharthan, Advaith. "An architecture for a text simplification system." Language Engineering Conference, 2002. Proceedings. IEEE, 2002.
- The dictionary definition of thesaurus at Wiktionary