mendacity

/mɛnˈdæsəti/

//mɛnˈdæsəti// noun

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

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

The verdict

“mendacity” is uncommon English (frequency #80,665 among 4,057 “M” headwords), classed as a noun. The kind of spelling people second-guess.

#80,665
frequency rank, English
4,057
“M” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - The fact or condition of being untruthful; dishonesty.

Corpus desk

Index EN-mendacity · mendacity · English

mendacity · rank #80,665 · 0 variants · 0 confusables

  • FREQ-RARE #80,665
  • LEN-LONG 9 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 4,057
  • PHOTO-FINISH megalomania

Nearest frequency peer: megalomania (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Long-tail ranks near “mendacity”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “mendacity” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for mendacity
PropertyValue
Headwordmendacity
LanguageEnglish
Part of speechNoun
IPA/mɛnˈdæsəti/
Letters9
Frequency rank#80,665
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “mendacity” in English

Word frequency stretches from the small set of words we reach for constantly (left) out to the long tail barely used once in a while (right).mendacityfalls in this rarity band:

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

Ticks step logarithmically, so each one marks a roughly tenfold drop in how often the word turns up. Rare peers in the same band: “megalomania” (#80,664), “merce” (#80,666), “merk” (#80,667). Among 4,057 “M” headwords, “mendacity” is #80,665. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

mendacity is uncommon English at frequency #80,665 among 4,057 “M” headwords, classed as anoun, transcribed /mɛnˈdæsəti/. Rarity is why readers land here mid-draft. 2 senses are on record.

mendacity doesn't appear in our generated misspelling index, suggesting the orthography follows predictable English patterns. Our dataset records no confusable match here, since its spelling is unusual enough that it doesn't cluster with a lookalike.

Etymologically, the entry records: From Late Latin mendacitas, from Latin mendāx (“deceitful, deceptive, lying”) + -itās (suffix forming nouns indicating a state of being). Mendāx is derived from mentior (“to deceive, lie”) (from mēns, mentis (“mind; intellect; judgment, reasoning”), from Pr… The correct English form is mendacity, spelled M-E-N-D-A-C-I-T-Y.

Definition

  1. 1
    The fact or condition of being untruthful; dishonesty.
  2. 2
    A deceit, falsehood, or lie.

Recorded use

Wiktionary examples

These source excerpts show how mendacity appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. Mendacity is not a uniform offence: it changes its colour according to the nature and substance of the offence to which it is rendered or endeavoured to be rendered subservient. Mendacity, employed in drawing down upon an innocent head the destroying sword of justice, is murder: murder, encompassed with all its correspondent terror. Mendacity, employed in…
  2. […] Treating the assertion of the witness as the effect, he [Pierre-Simon Laplace] considers as its two possible causes, the veracity or mendacity of the witness on the particular occasion, that is, the truth or falsity of the fact.

Etymology

From Late Latin mendacitas, from Latin mendāx (“deceitful, deceptive, lying”) + -itās (suffix forming nouns indicating a state of being). Mendāx is derived from mentior (“to deceive, lie”) (from mēns, mentis (“mind; intellect; judgment, reasoning”), from Proto-Indo-European *méntis (“thought”)) + -āx (suffix forming adjectives expressing a tendency or inclination), or from Proto-Indo-European *mend- (“to fault”).

This word in other languages

mentira(Español)Verlogenheit(Deutsch)falsidade(Português)

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 "mendacity"?
"mendacity" is spelled M-E-N-D-A-C-I-T-Y. The IPA pronunciation is /mɛnˈdæsəti/.
What does "mendacity" mean?
As a noun, "mendacity" means: The fact or condition of being untruthful; dishonesty.
How do you pronounce "mendacity"?
The IPA (International Phonetic Alphabet) transcription for "mendacity" is /mɛnˈdæsəti/. 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 "mendacity"?
From Late Latin mendacitas, from Latin mendāx (“deceitful, deceptive, lying”) + -itās (suffix forming nouns indicating a state of being). Mendāx is derived from mentior (“to deceive, lie”) (from mēns, mentis (“mind; intellect; judgment, reasoning”... 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.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "mendacity", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 9 letters (nearest by frequency rank).

mirabilis#80,674Miscavige#80,676monomeric#80,682longshore#80,631

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

Source: FrequencyWords open word-frequency list