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 an uncommon English word, ranked #88,600 in English word frequency and used as an adjective.

#88,600
frequency rank, English
10
letters

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Lying, untruthful or dishonest.

Key facts for mendacious
PropertyValue
Headwordmendacious
LanguageEnglish
Part of speechAdjective
IPA/mɛnˈdeɪʃəs/
Letters10
Frequency rank#88,600
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “mendacious” 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). mendacious 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 mendacious is 10 letters long, classified as an adjective, and transcribed in the International Phonetic Alphabet as /mɛnˈdeɪʃəs/. Corpus data places it at rank #88,600 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 2 distinct senses for this headword, so context determines which meaning a reader should apply.

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.

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.

Using “mendacious”

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

  • The one correct English spelling is M-E-N-D-A-C-I-O-U-S - every other letter order is a misspelling in standard orthography.
  • Say it as /mɛnˈdeɪʃəs/ (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