mendacity

noun

1. (uncountable)The fact or condition of being untruthful; dishonesty.

   “[…] 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.”

   “Big Daddy: […] Think of all the lies I got to put up with!—Pretenses! Ain't that mendacity? Having to pretend stuff you don't think or feel or have any idea of?”

   “So now the hard Brexiters say, with astonishingly cynical mendacity, that Britain would be better off going it alone.”

   “A shifty or unreliable politician may hide their mendacity behind deceit, fabrication on confabulation, or by rehearsed counter-attack that simply ignores the questions but makes imputations against the other.”

2. (countable)A deceit, falsehood, or lie.

   “The scandalous bronze-lacker age, of hungry animalisms, spiritual impotencies and mendacities, will have to run its course, till the Pit swallow it.”

   “Though the rebels had utterly failed in their purposes, having accomplished nothing but the temporary disabling of two lightly armed vessels, and had retreated before the approach of the only formidable vessel there, they formally, and with a mendacity equalled only by some of their own efforts in that direction, proclaimed that they had "driven out of sight, for a time, the entire hostile fleet," and that the blockade of the port of Charleston was raised.”

   “He would have you believe that every error we make is deliberate, that journalists have somehow ginned up a unified conspiracy of lies and mendacities against him.”