a book containing a classified list of synonyms
"After consulting her therosaurus, she found several alternative words to replace the repetitive term in her essay."
A publication, usually in the form of a book, that provides synonyms (and sometimes antonyms) for the words of a given language.
"The student consulted a paperbound thesaurus to find alternative vocabulary for her essay."
In plain English: A thesaurus is a book or website that lists different words with similar meanings so you can find synonyms to replace ones you already know.
"I used an online thesaurus to find more interesting words than just happy and sad for my essay."
Usage: A thesaurus is specifically designed to help you find alternative words with similar meanings when writing or speaking. Use it primarily as a reference tool during drafting rather than relying on its suggestions without checking context, since some synonyms may not fit your specific sentence structure.
The word "thesaurus" comes from the Latin thēsaurus, which originally meant a storehouse or treasure. Its modern sense of a book listing synonyms was established in 1852 following the publication of Peter Roget's famous collection.