Thesaurus Meaning: Here’s What It Means and How To Use It

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If you’ve seen the word thesaurus before and think your knowledge of its meaning, origin, and history may be lacking, then you’re in the right place. We’re here with the ultimate guide to the word thesaurus and how to use it

Thesaurus (the·sau·rus·es, plural the·sau·ri) is commonly seen and used in the English language and dictionaries everywhere, but it has an interesting history that you may not have known about. Let’s dive into this word of the day and unlock its rich history.

What Is the Definition of Thesaurus?

According to Oxford Languages, a thesaurus is a book that includes word lists. says these lists consist of groups of synonyms and other related words. 

In general, you would use a thesaurus to find synonyms of a specific word. 

An example of a thesaurus would be a book that includes subject headings or descriptions of words. You can expect a cross-reference system to help with document organization and retrieval purposes. 

What Is the Origin of the Word Thesaurus?

Thesaurus comes from Greek and Latin origin (Greek thēsauros) and (Latin thēsaurus), meaning “storehouse” or “treasury.” 

As most words do, thesaurus evolved over the years and has taken on a completely different meaning. Before thesaurus took on its current meaning, for a short while (in the middle ages) it was used as a way to describe a treasurer and was pronounced thesaurer

Thesaurus was also used as a way to describe a “dictionary,” so the meaning or definitions of words (not just synonyms), before it took on its new meaning.

What Is The History and Etymology of Thesaurus? 

The definition of a thesaurus is a book with synonyms of words, but thesaurus hasn’t always had this meaning. So, how did this word evolve?

We can thank Peter Mark Roget. Roget was an English psychologist and physician who studied literary texts. In 1852, Roget had the bright idea to write a book on English words and their synonyms. He assumed this would be a helpful education tool — and he thought correctly. 

The thesaurus was a project Roget took on after his long career, and it was a way for him to stay occupied during his retirement. 

This exciting new resource housed 15,000 words into six different primary categories, and he continued to add words and categories as more editions were published. The latest publication of the Roget Thesaurus (the eighth edition) had over 1,075 word categories! 

Once universities heard about the thesaurus, students and professors were ecstatic. The thesaurus would become a necessary studying tool and reference book. 

Of course, the dictionary of the English language already existed and were especially useful, but the thesaurus was new and exciting. It could advance everyone’s knowledge of the English language exponentially and enhance people’s writing skills and vocabulary.

Eventually, the thesaurus would become every writer’s best friend. Anything that can enhance someone’s lexicon is a useful resource. 

The Thesaurus Today

Just as the word itself evolved, so has Roget’s Thesaurus. The thesaurus started out as one book with just over 15,000 words, but today there are tons of thesaurus books, as well as online options. Thanks to word processing algorithms, the synonym or antonym to any word is just a Google search away. 

There is, of course,, but there are other thesaurus options as well, like the Oxford Pocket American Dictionary and Thesaurus or the Longman Thesaurus of American English. 

Almost any dictionary you buy or use online will offer a thesaurus as well.

When Should You Use the Word Thesaurus?

It’s always easier to understand the usage and context of words like a thesaurus when you have sentences to compare and contrast. 

Here are some examples of the word thesaurus being used in sentences:

A thesaurus is an educational tool that can improve writing.

A thesaurus is similar to a dictionary but isn’t the same thing.

A thesaurus offers terms for concepts and presents the relationships between terms.

He needed a thesaurus to formulate a well-written response.

A thesaurus module that is integrated into the software used for database creation is extremely useful

 A thesaurus is usually tailored to meet the specifics of an application.

The thesaurus functions not only as a retrieval aid, but also as a reference facility.

A spell checker, word count feature, and thesaurus are all included, and the program can adjustheaders and footers.

 The relationship displayed in a thesaurus is often more in-depth than that in a subject heading. 

The thesaurus may be kept in machine-readable form, with sections printed only as required.

 How can I find antonyms in the thesaurus?

 Do I need a thesaurus to complete this assignment well?

 A thesaurus is a useful book of synonyms and antonyms.

Be careful when using a thesaurus; its results aren’t always the perfect word for the sentence.

A dictionary of synonyms is called a thesaurus.

What Are the Synonyms of Thesaurus?

Almost every word has a few synonyms you can find in a thesaurus, and here are the synonyms of the word thesaurus itself: 

  • Wordfinder
  • Wordbook 
  • Synonym

The Takeaway

The thesaurus has an interesting history and is a useful educational tool. You probably use a thesaurus more often than you realize. While they can be useful, they aren’t a cheat sheet. You still need to be knowledgeable on what you’re writing. 

Sometimes, a thesaurus will give you words that don’t really make the most sense — especially web-based options. As long as you pay attention, a thesaurus is a fantastic way to elevate your writing and leave you looking like a walking dictionary. 


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Thesaurus Definition & Meaning |

STOREHOUSE | definition in the Cambridge English Dictionary

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