thesaurus

/θɪˈsɔːɹəs/

//θɪˈsɔːɹəs// noun

By · According to Wiktionary data (CC BY-SA) ·

"thesaurus" is a 9-letter English headword indexed on PlainSpell.

The verdict

“thesaurus” is a moderately-common English word, ranked #33,879 in English word frequency and used as a noun.

#33,879
frequency rank, English
9
letters
13
tracked misspellings

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A publication that provides synonyms (and sometimes antonyms and other semantic relations) for the words of a given language.

Key facts for thesaurus
PropertyValue
Headwordthesaurus
LanguageEnglish
Part of speechNoun
IPA/θɪˈsɔːɹəs/
Letters9
Frequency rank#33,879
Misspellings tracked13
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “thesaurus” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). thesaurus lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Spelling & Dictionary Insight

The English entry for thesaurus is 9 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /θɪˈsɔːɹəs/. Corpus data places it at rank #33,879 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 3 distinct senses for this headword, so context determines which meaning a reader should apply.

Our generated misspelling index lists 13 likely wrong-spelling variants for thesaurus, with forms such as "htesaurus", "tehsaurus", and "theasurus". Each of these forms differs from the correct spelling by one small edit: a doubled letter, a dropped silent letter, or a substituted vowel. No close-neighbour confusable shows up for this headword in our dataset, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: 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. Doubl… The correct English form is thesaurus, spelled T-H-E-S-A-U-R-U-S.

Definition

  1. 1
    A publication that provides synonyms (and sometimes antonyms and other semantic relations) for the words of a given language.
  2. 2
    A dictionary or encyclopedia.
  3. 3
    A hierarchy of subject headings: canonical titles of themes and topics, the titles serving as search keys.

Etymology

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.

This word in other languages

tesoro(Español)dictionnaire des synonymes(Français)Thesaurus(Deutsch)

Common misspellings

Also misspelled as: htesaurus,tehsaurus,theasurus,thesaruus,thesaurrus,thesaursu,thesauruss,thesauurs,thessaurus,thesuarus,thhesaurus,thseaurus,tthesaurus

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of thesaurus - measured in single-character edits (insert, delete, or substitute a letter). Larger bars are easier to catch; one-edit slips are the sneakiest.

htesaurus2tehsaurus2theasurus2thesaruus2thesaurrus1thesaursu2thesauruss1thesauurs2
Edit distance from "thesaurus"

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "thesaurus"?
"thesaurus" is spelled T-H-E-S-A-U-R-U-S. The IPA pronunciation is /θɪˈsɔːɹəs/.
What does "thesaurus" mean?
As a noun, "thesaurus" means: A publication that provides synonyms (and sometimes antonyms and other semantic relations) for the words of a given language.
What are common misspellings of "thesaurus"?
Common misspellings include "htesaurus", "tehsaurus", "theasurus", "thesaruus", "thesaurrus". The correct spelling is "thesaurus".
How do you pronounce "thesaurus"?
The IPA (International Phonetic Alphabet) transcription for "thesaurus" is /θɪˈsɔːɹəs/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "thesaurus"?
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 1... See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Using “thesaurus”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is T-H-E-S-A-U-R-U-S - every other letter order is a misspelling in standard orthography.
  • Say it as /θɪˈsɔːɹəs/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Browse more English words and confusable pairs in the same reference. English words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list