insincerity

n. lack of sincerity, lack of honesty, deceitfulness

Sincerity is the virtue of speaking truly about one's feelings, thoughts, desires. Sincere expression carries risks to the speaker, since the ordinary screens used in everyday life are opened to the outside world. At the same time, we expect our friends, our lovers, our leaders "to be sincere."Surprisingly, sincerity has not always been regarded a virtue in Western culture. It appears to have become an ideal for the first time in Europe and North America in the 17th century; and it gained considerable momentum during the Romantic movement, when sincerity was first celebrated as an artistic and social ideal. Indeed, in mid- to late-nineteenth century America, sincerity was an idea reflected in mannerisms, hairstyles, women's dress, and the literature of the time.
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Noun
1. the quality of not being open or truthful; deceitful or hypocritical
(synonym) falseness
(antonym) sincerity
(hypernym) untruthfulness
(hyponym) hypocrisy

(n.)
The quality of being insincere; want of sincerity, or of being in reality what one appears to be; dissimulation; hypocritical; deceitfulness; hollowness; untrustworthiness; as, the insincerity of a professed friend; the insincerity of professions of regard.
  

Synonyms and related words:
Tartuffery, Tartuffism, affectation, affectedness, airs, airs and graces, apparent soundness, artfulness, artificiality, cant, casuistry, circularity, craftiness, credibility gap, crossed fingers, deceitfulness, disingenuousness, distortion, emptiness, equivocalness, equivocation, evasive reasoning, facade, fallaciousness, fallacy, false front, false piety, false show, falseheartedness, falseness, feigned belief, flattering tongue, forswearing, fraud, front, goody-goodiness, gush, hollow mockery, hollowness, hypocrisy, image, intrigue, jesuitism, jesuitry, mannerism, mealymouthedness, mere show, misapplication, mockery, mummery, mystification, obfuscation, obscurantism, oiliness, oversubtlety, perjury, perversion, pharisaicalness, pharisaism, philosophism, pietism, pietisticalness, piety, piousness, plausibility, plausibleness, pretense, pretension, prunes and prisms, public image, put-on, putting on airs, rationalization, religionism, religiosity, sanctimoniousness, sanctimony, self-righteousness, sham, sharp practice, show, slobber, smarm, snivel, snuffle, sophism, sophistical reasoning, sophistication, sophistry, special pleading, speciosity, specious reasoning, speciousness, stylishness, subtlety, that flattering unction, tongue in cheek, uncandidness, uncandor, unction, unctuousness, unfrankness, unnaturalness, unsincereness, untruthfulness, vicious circle, vicious reasoning