(a.) Fallacious; specious; not sound\.

Machiavellian Machiavellic acute apparently sound arch artful astute cagey canny casuistic clever colorable crafty cunning cute deceitful deceptive deep deep-laid designing diplomatic dishonest disingenuous empty fallacious feline foxy guileful hollow illusive ingenious insidious insincere inventive jesuitic knowing mealymouthed overrefined oversubtle pawky philosophicojuristic philosophicoreligious philosophistic plausible politic ready resourceful scheming serpentine sharp shifty shrewd slick slippery sly smooth snaky sneaky sophistic specious stealthy strategic subtile subtle supple tactical tongue in cheek trickish tricksy tricky uncandid unfrank unserious vulpine wary wily