adjective

giving an appearance or impression different from the true one; misleading.

he put the question with deceptive casualness

misleading,illusory,illusive,illusionary,ambiguous,deceiving,delusive,distorted,specious,deceitful,duplicitous,fraudulent,counterfeit,sham,bogus,cheating,underhand,cunning,crafty,sly,guileful,scheming,perfidious,treacherous,Machiavellian,dissembling,disingenuous,untrustworthy,unscrupulous,unprincipled,dishonest,untruthful,lying,mendacious,insincere,false,crooked,sharp,shady,slippery,sneaky,tricky,foxy,bent,slim,subtle,hollow-hearted,false-hearted,double-faced,truthless,Punic