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1. Lying; untruthful: a mendacious child.
2. False; untrue: a mendacious statement. See Synonyms at dishonest.

[From Latin mendācium, lie, from mendāx, mendāc-, mendacious.]

men·da′cious·ly adv.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(mɛnˈdeɪ ʃəs)

1. telling lies, esp. habitually; dishonest.
2. false or untrue: a mendacious report.
[1610–20; < Latin mendāx; see -acious]
men•da′cious•ly, adv.
men•da′cious•ness, n.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.mendacious - given to lying; "a mendacious child"
untruthful - not expressing or given to expressing the truth; "the statement given under oath was untruthful"; "an untruthful person"
2.mendacious - intentionally untrue; "a mendacious statement"
false - not in accordance with the fact or reality or actuality; "gave false testimony under oath"; "false tales of bravery"
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.


adjective lying, false, untrue, fraudulent, dishonest, deceptive, deceitful, insincere, duplicitous, perjured, perfidious, fallacious, untruthful politicians issuing mendacious claims and counter-claims
true, genuine, honest, truthful
Collins Thesaurus of the English Language – Complete and Unabridged 2nd Edition. 2002 © HarperCollins Publishers 1995, 2002


Given to or marked by deliberate concealment or misrepresentation of the truth:
The American Heritage® Roget's Thesaurus. Copyright © 2013, 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


[menˈdeɪʃəs] ADJ (frm) → mendaz
Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005


Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007
References in classic literature ?
At the most, I regard thee as the ventriloquist of the earth: and ever, when I have heard subversive and spouting devils speak, I have found them like thee: embittered, mendacious, and shallow.
"Church?" answered I, "that is a kind of state, and indeed the most mendacious. But remain quiet, thou dissembling dog!
Alexander I- the pacifier of Europe, the man who from his early years had striven only for his people's welfare, the originator of the liberal innovations in his fatherland- now that he seemed to possess the utmost power and therefore to have the possibility of bringing about the welfare of his peoples- at the time when Napoleon in exile was drawing up childish and mendacious plans of how he would have made mankind happy had he retained power- Alexander I, having fulfilled his mission and feeling the hand of God upon him, suddenly recognizes the insignificance of that supposed power, turns away from it, and gives it into the hands of contemptible men whom he despises, saying only:
"Yes--what the mendacious family chronicles call extinct in the male line--that is, gone down--gone under."
Mildred had become great friends with her and had given her an elaborate but mendacious account of the circumstances which had brought her to the pass she was in.
The mendacious captain was perfectly well aware that an affair of honor always makes a man stand well in the eyes of a woman.
On all fours amongst the puddles, wet and begrimed, like a sort of amphibious and domestic animal living in ash-bins and dirty water, she uttered the usual exordium: "It's all very well for you, kept doing nothing like a gentleman." And she followed it with the everlasting plaint of the poor, pathetically mendacious, miserably authenticated by the horrible breath of cheap rum and soap-suds.
To the morality of a Western reader an account of these meetings would wear perhaps the sinister character of old legendary tales where the Enemy of Mankind is represented holding subtly mendacious dialogues with some tempted soul.
If the Bill passes the House of Lords, the grand plan of a mendacious PM and his maligned schemer Dominic Cummings will be in ruins.
Of course, most of us would never believe a word spoken by either of these mendacious fools, but sadly their cheap rhetoric does have a malign influence in the crazy world we currently live in.
Does this mean you're going to lay down your pen and head off into the sunset on the mendacious Brexit bus?
Rapacious and mendacious physicians have apparently traded their Hippocratic Oath for the Hypocrite Oath of minting money and acting more like ruthless bank directors.