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1. Working or spreading harmfully in a subtle or stealthy manner: insidious rumors; an insidious disease.
2. Intended to entrap; treacherous: insidious misinformation.
3. Beguiling but harmful; alluring: insidious pleasures.

[From Latin īnsidiōsus, from īnsidiae, ambush, from īnsidēre, to sit upon, lie in wait for : in-, in, on; see in-2 + sedēre, to sit; see sed- in Indo-European roots.]

in·sid′i·ous·ly adv.
in·sid′i·ous·ness n.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.insidiousness - subtle and cumulative harmfulness (especially of a disease)
harmfulness, injuriousness - destructiveness that causes harm or injury
2.insidiousness - the quality of being designed to entrap
perfidiousness, perfidy, treachery - betrayal of a trust
References in periodicals archive ?
Topics on the list take into account factors such severity, frequency, breadth, insidiousness, profile, and preventability.
I recognise, with reflection, the insidiousness of the white societal power and privilege held by those of us who are white, which includes those not-so white but benefiting from the racial hierarchy (Fine, 2004).
When I realized the depth and insidiousness of the propaganda in the western media when it comes to all other cultures, I decided to find out for myself.
What follows is a critique of the effect of Western aid, the naivete of 'doing good' and the insidiousness of racism, all of which are more interesting than the murder mystery.
The subplot of Herrlichkeit unfolds in an extended meditation on modernity's loss of a faithful sensibility for the beauty of the incarnate form, a reflection on the insidiousness of sin viewed through the lens of aesthetics.
Wunker first talks about it in a post that comes immediately on the heels of Morrison's, titled "Being Frank Feels Risky: Notes from the Non-tenured Stream" In it, Wunker talks of her reluctance to admit the exhaustion of a 3/3 academic load, garnished with research grants applications, and topped with the insidiousness of job insecurity that never leaves a sessional.
Through this exercise, I realized it is Common Core's complexity that prevents a full understanding of its insidiousness.
She said that politically correct language often hides the insidiousness still present.
Still, biographers and critics take Bill's word on Marge, failing to see, as Stoneback reminds us, "that one central concern of the stories is the very insidiousness of Bill's patronizing attitudes" (78).
Capital is a consistently engrossing read, encompassing topics including the stunning comeback that inherited wealth has made in today's advanced economies, the dubiousness of the economic theory that a worker's wage is equal to his or her marginal productivity, the moral insidiousness of meritocratic justifications of inequality, and more.
It usefully points to the insidiousness of the juridical and religious model structuring the mode of address under interrogation, and casting its pall over later scenes of truth-telling.
Many religious groups condemned the film while sometimes assessing its qualities, perhaps to warn against its insidiousness.