thesaurus
the·saur·us/θɪˈsɔːɹəs/noun
thesaurus is spelled T-H-E-S-A-U-R-U-S: 9 letters and 3 syllables (the·saur·us). It appears about once in every 1 million words in written English, the 33,636th most frequent word form (wordfreq, 2021 data). As a noun, thesaurus means “A publication that provides synonyms (and sometimes antonyms and other semantic relations) for the words of a given language” (English Wiktionary, September 2026). The plural of thesaurus is thesauri or thesauruses.
How many letters and syllables are in thesaurus?
| Letters | 9: T-H-E-S-A-U-R-U-S |
|---|---|
| Syllables | 3: the·saur·us |
| In writing | about once in every 1 million words; the 33,636th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is thesaurus?
Thesaurus appears about once in every 1 million words in written English, the 33,636th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce thesaurus?
- /θɪˈsɔːɹəs/
- British /θɪˈsoːɹəs/
Thesaurus has 3 syllables, split the·saur·us in writing.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-thesaurus.wav, Wikimedia Commons (author and licence on each file's page).
Forms of thesaurus
- thesauri plural
- thesauruses plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does thesaurus mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
A publication that provides synonyms (and sometimes antonyms and other semantic relations) for the words of a given language.
"Roget" is the leading brand name for a print English thesaurus that lists words under general concepts rather than just close synonyms.
- 2
archaicA dictionary or encyclopedia.
- 3
A hierarchy of subject headings: canonical titles of themes and topics, the titles serving as search keys.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Thesaurus in Spanish, French, German and Portuguese
In the sense book of synonyms:
| Language | Words |
|---|---|
| French | dictionnaire des synonymes, thésaurus, dictionnaire de notions, dictionnaire par ordre de matières |
| German | Thesaurus, Begriffswörterbuch, Sachgruppenwörterbuch, Synonymwörterbuch |
| Portuguese | dicionário de sinónimos, dicionário de sinônimos, tesauro, thesaurus |
| Spanish | diccionario de sinónimos, tesoro |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does thesaurus come from?
16th century, borrowed from Latin thēsaurus, from Ancient Greek θησαυρός (thēsaurós, “storehouse, treasure”); its current English usage/meaning was established soon after the publication of Peter Roget's Thesaurus of English Words and Phrases in 1852. Doublet of treasure.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).