Thesaurus (noun)

1. A reference work (such as a book or website) that lists words and phrases, along with their synonyms and antonyms, usually in alphabetical order.
2. A collection of words or terms relating to a particular subject or category, typically in order to assist in the selection of appropriate words.

Origin:

Late latin thesaurus, from greek thesauros "treasury, storehouse".

Examples:

1. The thesaurus is a helpful tool for writers to find just the right word for their writing.
2. I often consult a thesaurus when I am trying to find a synonym for a word I am using in a text.
3. The thesaurus helps me to broaden my vocabulary and make my writing more interesting.
4. The website is a digital thesaurus that provides synonyms, antonyms, and definitions for various words.
5. She opened the thesaurus to find another word for 'love' because she wanted to avoid using it too often in her writing.