insidiousness
nounEtymology From insidious + -ness.
1
Usually A surreptitious harmfulness, quality of entrapment, or treacherousness; the characteristic of being insidious.
- This lent a new insidiousness to his temptation, since her contempt would be a refuge from his own.1900, Edith Wharton, chapter 8, in The Touchstone: