1. (a.) Not being in truth what one appears to be; not sincere; dissembling; hypocritical; disingenuous; deceitful; false; -- said of persons; also of speech, thought; etc.; as, insincere declarations.

2. (a.) Disappointing; imperfect; unsound.

Machiavellian Tartuffian Tartuffish adulatory affected ambidextrous apparently sound artful artificial bland blandishing blarneying buttery cajoling calculating canting casuistic colorable complimentary courtierly courtly crafty crooked cunning deceitful deceptive dishonest disingenuous dissembling double double-dealing duplicitous empty evasive fair-spoken faithless fallacious FALSE falsehearted fawning fine-spoken flattering forsworn foxy fulsome goody goody-goody gushing histrionic holier-than-thou hollow honey-mouthed honey-tongued honeyed hypocritical illusive insinuating jesuitic la-di-da lying maniere mannered mealymouthed mendacious obsequious oily oily-tongued overacted overdone overrefined oversubtle perfidious perjured pharisaic philosophistic pietistic pious plausible pretentious sanctified sanctimonious scheming self-righteous shifty slick slimy slippery slobbery sly smarmy smooth smooth-spoken smooth-tongued sniveling soapy soft-soaping sophistic sophistical specious stagy sycophantic theatrical tongue in cheek treacherous tricky two-faced uncandid unctuous underhanded unfrank ungenuine unnatural unserious unsincere untruthful vulpine wheedling wily