From Greek (1823), from Greek 'thēsaurós (θησαυρός)' ("store, treasure, treasure house").
A book of synonyms and related words; broadly, a treasury or storehouse of knowledge.
From Latin 'thēsaurus' (treasury, storehouse, hoard), from Greek 'thēsaurós' (θησαυρός, a store, treasure, treasury). The word was used in its literal sense of 'treasure house' in English from the 1820s. Peter Mark Roget published his famous 'Thesaurus of English Words and Phrases' in 1852, which cemented the word's modern meaning as a reference book of synonyms. Roget, a physician and polymath, spent nearly fifty years organizing words by concept