About National Thesaurus Day
National Thesaurus Day falls on January 18th. The date honors the creator of the thesaurus: Peter Mark Roget. Roget was born on January 18th, 1779.
Roget became known for his creation of the "Thesaurus of English Words and Phrases Classified and Arranged so as to Facilitate the Expression of Ideas or Assist in Literary Composition", or just Thesaurus of English Words and Phrases for short in 1852.
Today it is better known as Roget’s Thesaurus. Roget began working on the book in 1846, six years after retirement from a medical career.
Roget was also the inventor of the "log-log" slide rule. He was born in London and died at West Malvern, Worcestershire, England, on September 12th 1869.
A thesaurus is a synonym dictionary. It 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.
The word "thesaurus" comes from Latin thēsaurus, which in turn comes from Greek thēsauros, meaning 'treasure, treasury, storehouse'.