Mendacious
adjective /menˈdeɪʃəs/ — Given to lying; untruthful by habit.
Definition
Not telling the truth; disposed to deceiving — using lies as a regular rather than exceptional mode of communication.
Beyond the definition
Mendacious is the formal word for a habitual liar — not someone who lied once under pressure, but someone for whom untruth is a default. It carries the weight of character judgment, not just description of an act.
Origin & history
From Latin mendax (lying, false), from mentiri (to lie). Related to mendacity (the quality of lying) and mendacium (a lie). The Latin root also gives us 'amend' — from the same idea of correcting what is false.
Example sentences
Illustrative sentences for learning, not verified community posts or sourced quotations.
The politician's mendacious campaign statements were carefully documented and later proved false.
She found him mendacious in small ways that made her question everything he said.
A mendacious report was submitted to the commission — a fact that came to light years later.
How to use it
This entry uses an adjective. Follow the examples for the nouns it describes and its position in the sentence.
Choose “Mendacious” when the meaning fits your context: Not telling the truth; disposed to deceiving — using lies as a regular rather than exceptional mode of communication.
Synonyms
dishonest, untruthful, deceitful, lying, duplicitous
Antonyms
truthful, honest, candid, veracious, sincere
Related words
- duplicity
- perfidious
- dissembling
- prevarication
Mendacious vs dishonest
Dishonest covers any lapse of honesty — a lie told under pressure, a withheld truth, an inflated claim. Mendacious is a character judgment: it implies that lying is not occasional but habitual, a default mode of communication rather than an exception. A dishonest person can be caught in a specific lie; a mendacious person lies as a matter of course. Dishonest describes an act; mendacious describes a disposition.
Questions about this word
What does "Mendacious" mean?
Mendacious is adjective meaning: Given to lying; untruthful by habit.. Not telling the truth; disposed to deceiving — using lies as a regular rather than exceptional mode of communication.
Where does the word "Mendacious" come from?
From Latin mendax (lying, false), from mentiri (to lie). Related to mendacity (the quality of lying) and mendacium (a lie). The Latin root also gives us 'amend' — from the same idea of correcting what is false.