insidious Synonyms

pernicious deceitful deceptive treacherous wily designing subtle sly guileful crafty artful underhand sneaky sneaking snaky smooth faking one out slick shrewd shifty scheming stealthy subtile vulpine tricky tricksy treasonable surreptitious duplicitous machiavellian obliquitous wormlike not straightforward playing games puckish perilous cunning crooked covert corrupt clever circumventive canny calculating beguiling backhanded astute dangerous deep delusory