INSINCERE

adj. hypocritical, dishonest, dissembling, deceptive, disingenuous, deceitful, untruthful, false, artificial, ungenuine, treacherous, perfidious, faithless, double-dealing, duplicitous, two-faced, Janus-faced, lying, mendacious, sly, Machiavellian, cunning, crafty, slick, foxy, vulpine, wily, artful, evasive, shifty, time-serving, unctuous, slimy, slippery, tricky, underhanded, crooked, Colloq phoney or US also phony From the first act I thought Iago insincere