1.  falsity(n = noun.state) falseness - the state of being false or untrue; "argument could not determine its truth or falsity"
is a kind of irreality, unreality
has particulars: spuriousness
Antonym: truth
Derived forms adjective false₁₀, adjective false₂, adjective false₅, verb falsify₄, verb falsify₃, verb falsify₁, verb falsify₂

2.  falsity(n = noun.communication) falsehood, untruth - a false statement;
is a kind of statement
has particulars: dodge, dodging, scheme, lie, prevarication, fable, fabrication, fiction, deceit, deception, misrepresentation, contradiction, contradiction in terms
Derived forms adjective false₄, adjective false₁, verb falsify₄, verb falsify₁

1.  The quality of being false; coutrariety or want of conformity to truth. [1913 Webster]
"Probability does not make any alteration, either in the truth or falsity of things." [1913 Webster]

2.  That which is false; falsehood; a lie; a false assertion. [1913 Webster]
"Men often swallow falsities for truths."

N  falsehood, falseness, falsity, falsification, deception, untruth, guile, lying, untruth, guile, lying, misrepresentation, mendacity, perjury, false swearing, forgery, invention, fabrication, subreption, covin, perversion of truth, suppression of truth, suppressio veri, perversion, distortion, false coloring, exaggeration, prevarication, equivocation, shuffling, fencing, evasion, fraud, suggestio falsi, mystification, simulation, dissimulation, dissembling, deceit, blague, sham, pretense, pretending, malingering, lip homage, lip service, mouth honor, hollowness, mere show, mere outside, duplicity, double dealing, insincerity, hypocrisy, cant, humbug, jesuitism, jesuitry, pharisaism, Machiavelism, organized hypocrisy, crocodile tears, mealy-mouthedness, quackery, charlatanism, charlatanry, gammon, bun-kum, bumcombe, flam, bam, flimflam, cajolery, flattery, Judas kiss, perfidy, il volto sciolto i pensieri stretti, unfairness, artfulness, misstatement, false, deceitful, mendacious, unveracious, fraudulent, dishonest, faithless, truthless, trothless, unfair, uncandid, hollow-hearted, evasive, uningenuous, disingenuous, hollow, sincere, Parthis mendacior, forsworn, artificial, contrived, canting, hypocritical, jesuitical, pharisaical, tartuffish, Machiavelian, double, double tongued, double faced, double handed, double minded, double hearted, double dealing, Janus faced, smooth-faced, smooth spoken, smooth tongued, plausible, mealy-mouthed, affected, collusive, collusory, artful, perfidious, spurious, untrue, falsified, covinous, falsely, a la tartufe, with a double tongue, silly, blandae mendacia lingua, falsus in uno falsus in omnibus, I give him joy that's awkward at a lie, la mentira tiene las piernas cortas, O what a goodly outside falsehood hath.