The Simple English Wikipedia has an article on: Thesaurus Pronunciation IPA (key): /θɪˈsɔːrəs/ Audio (UK)(file) Noun Singular thesaurus Plural thesauruses or thesauri (countable) A thesaurus is a book which lists synonyms (different words which have the same meaning). A thesaurus usually groups together synonymous words such as schadenfreude and epicaricacy together under a single heading. Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads