Definition of thesaurus in English:


nounPlural thesauruses, Plural thesauri

  • 1A book that lists words in groups of synonyms and related concepts.

    • ‘Parents can choose to filter out the rude words they scoured thesauruses to find when they were children, and there is an audio option, so you can hear how to articulate your new-found vocabulary.’
    • ‘You just need to type in any keywords related to your area of interest and then use the built in thesaurus to find related keywords and synonyms.’
    • ‘Use your word processor's thesaurus to find synonyms for ‘said’ and use them to convey a speaker's frame of mind or actions to the reader.’
    • ‘I have ransacked my thesaurus for a word that does justice to the terrible events that made up what history will know for ever as The Battle of Old Trafford, and I have come up with the mot juste.’
    • ‘The destruction here is indescribable and the thesaurus has no words for what we have seen.’
    • ‘The thesaurus provides synonyms, antonyms and related words, and is accessed by just right-clicking on the word to be looked up, and selecting ‘Thesaurus’ from the menu.’
    • ‘He might have meant displayed, or perhaps even reflected, but he didn't mean ‘mirrored’; once again he has picked a word out of his thesaurus that he doesn't know how to use.’
    • ‘My thesaurus lists all these unattractive equivalents: indolent, somnolent, lumpish, torpid, lax, good-for-nothing… and so on.’
    • ‘Finally, I'd like to know if you've replaced editors with the spell checker and thesaurus of your word processor.’
    • ‘A dictionary, a thesaurus or synonym finder, a good grammar book and language tapes are good investments for anyone wishing to develop or maintain language skills.’
    • ‘Without commenting, Craig asked one student to look the word up in a dictionary and another student to find the word in a thesaurus.’
    • ‘According to my thesaurus here, crisp is synonymous with cold.’
    • ‘There were atlases, dictionaries, reference books, and thesauruses, fantasies, biographies, tragedies, and tales of horror, mysteries, volumes of poetry, encyclopedias, and novels.’
    • ‘My thesaurus gives the following synonyms: self-satisfaction, conceit, egotism, self-importance, haughtiness, vanity, hubris, arrogance.’
    • ‘Give yourself time to brainstorm great website title ideas, asking friends and family for inspiration, and using a thesaurus for some dazzling words.’
    • ‘These include thesauri, subject headings lists, classification systems and other categorization schemes used to index or organize different databases.’
    • ‘Gone are the days of listing an entire thesaurus of descriptive terms in the site's meta tags to gain a high search-engine rank.’
    • ‘Unlike a conventional thesaurus, this book concentrates on word groups, and not on individual words.’
    • ‘And it's a serviceable, pleasant, if unspectacular record, the kind of album that has you searching the thesaurus for more synonyms for ‘good’.’
    • ‘A thesaurus groups words that are similar in meaning.’
    wordfinder, wordbook, synonym dictionary, synonym lexicon
    View synonyms
    1. 1.1archaic A dictionary or encyclopedia.


Late 16th century: via Latin from Greek thēsauros ‘storehouse, treasure’. The original sense ‘dictionary or encyclopedia’ was narrowed to the current meaning by the publication of Roget's Thesaurus of English Words and Phrases (1852).