mendacious

/mɛnˈdeɪʃəs/

//mɛnˈdeɪʃəs// adj

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

"mendacious" is a 10-letter English headword indexed on PlainSpell.

The verdict

“mendacious” is uncommon English (frequency #88,600 among 4,057 “M” headwords), classed as an adjective. The kind of spelling people second-guess.

#88,600
frequency rank, English
4,057
“M” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Lying, untruthful or dishonest.

Corpus desk

Index EN-mendacious · mendacious · English

mendacious · rank #88,600 · 0 variants · 0 confusables

  • FREQ-RARE #88,600
  • LEN-MEGA 10 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 4,057
  • PHOTO-FINISH Memnon

Nearest frequency peer: Memnon (-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 “mendacious”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

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

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for mendacious
PropertyValue
Headwordmendacious
LanguageEnglish
Part of speechAdjective
IPA/mɛnˈdeɪʃəs/
Letters10
Frequency rank#88,600
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “mendacious” in English

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

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

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Rare peers in the same band: “Memnon” (#88,599), “menfolk” (#88,601), “McGahn” (#88,595). Among 4,057 “M” headwords, “mendacious” is #88,600. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

mendacious is uncommon English at frequency #88,600 among 4,057 “M” headwords, classed as anadjective, transcribed /mɛnˈdeɪʃəs/. Rarity is why readers land here mid-draft. 2 senses are on record.

No generated misspelling entries exist for mendacious in our index, since its letter sequence doesn't invite the usual edit-distance slips. Our confusable-pair dataset has no match for it, a sign it's visually distinctive enough not to be mixed up with another word.

Etymologically, the entry records: Borrowed from Middle French mendacieux, from Latin mendācium (“lie, untruth”), from mendāx (“lying”). The correct English form is mendacious, spelled M-E-N-D-A-C-I-O-U-S.

Definition

  1. 1
    Lying, untruthful or dishonest.
  2. 2
    False or untrue.

Recorded use

Wiktionary examples

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

  1. He was dismissed as a mendacious witness.
  2. mendacious propaganda

Etymology

Borrowed from Middle French mendacieux, from Latin mendācium (“lie, untruth”), from mendāx (“lying”).

This word in other languages

mentiroso(Español)fallacieux(Français)lügnerisch(Deutsch)mentiroso(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 "mendacious"?
"mendacious" is spelled M-E-N-D-A-C-I-O-U-S. The IPA pronunciation is /mɛnˈdeɪʃəs/.
What does "mendacious" mean?
As an adjective, "mendacious" means: Lying, untruthful or dishonest.
How do you pronounce "mendacious"?
The IPA (International Phonetic Alphabet) transcription for "mendacious" is /mɛnˈdeɪʃəs/. 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 "mendacious"?
Borrowed from Middle French mendacieux, from Latin mendācium (“lie, untruth”), from mendāx (“lying”). 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 "mendacious", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 10 letters (nearest by frequency rank).

McConville#88,592maximalist#88,591microfiche#88,610marginalia#88,581

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

Source: FrequencyWords open word-frequency list