Etymology 16th century from Greek θησαυρός storehouse, treasure. Its current usage became the established use with the publication of Peter Roget's Thesaurus of English Words and Phrases in 1852. Noun A publication, usually in the form of a book, which references the words of a given language, or languages, and gives possible alternatives to their use. (Archaic): a dictionary or encyclopedia Translations Dutch: thesaurus German: Thesaurus m Esperanto: tezaŭro Japanese: シソーラス (shisōrasu), 類語辞典 (ruigo jiten) Spanish: tesauro Swedish: synonymordbok References See Wikipedia article about thesaurus.