The constancy and the strength of temptation, and the insidiousness of the arguments it was supported by, has been proverbial.
We suspected not that deceit, insidiousness, and slavery were to be found beneath the sun.
She saw O-liver start from his chair and sink back, helpless against the insidiousness of this attack.
Its insidiousness makes it exceedingly difficult to recognize.
They believed in the personality, activity and insidiousness of the Devil.
The insidiousness of its design has been equalled only by the shameless manner of its being carried into execution.
As to his character: it is too bad to associate him with so much craft and insidiousness.
Indeed, it is perhaps more damaging in its secondary effects because of its insidiousness.
insidious in·sid·i·ous (ĭn-sĭd'ē-əs)
Being a disease that progresses with few or no symptoms to indicate its gravity.