working or spreading in a hidden and usually injurious way
<adj.all> glaucoma is an insidious disease a subtle poison
Insidious \In*sid"i*ous\, a. [L. insidiosus, fr. insidiae an ambush, fr. insidere to sit in; pref. in- + sedere to sit: cf. F. insidieux. See {Sit}.] 1. Lying in wait; watching an opportunity to insnare or entrap; deceitful; sly; treacherous; -- said of persons; as, the insidious foe. ``The insidious witch.'' --Cowper.
2. Intended to entrap; characterized by treachery and deceit; as, insidious arts.
The insidious whisper of the bad angel. --Hawthorne.
3. Acting or proceeding unobserved or in a seemingly harmless manner, but slowly or eventually doing great damage; as, an insidious disease; an insidious plot. [PJC]
{Insidious disease} (Med.), a disease existing, without marked symptoms, but ready to become active upon some slight occasion; a disease not appearing to be as bad as it really is.
It is part of "insidious designs" by Israel, he said.
"There are so many approaches to this insidious disease, but attitude certainly can enhance the healing process," says Alan Ewalt, senior vice president of human resources at National Medical Enterprises.
"The death certificates blame persons unknown and some of the stories are so insidious that I understand why over the years people in the town didn't want to talk about it," said Peggy Germain, a former Calumet council member.
As an American, I was outraged by the inequities of the system, and saw it as an insidious method of maintaining class distinctions.
"The death certificates blame `persons unknown,' and some of the stories are so insidious that I understand why over the years people in the town didn't want to talk about it," she said.
Inflation is insidious, occurring right under the noses of people but somehow obscured from their eyes.
This brings us to the second insidious function of central banks: fixing the exchange rate.
But relief workers say that the most common, and most insidious, are the so-called butterfly mines, light camouflaged explosives strewn like autumn leaves from helicopters and planes, and the booby traps planted randomly around villages.
"There's nothing insidious about a marketing vehicle that reaches out to kids and doesn't cost anything," insists Ms. Boehm.
Finally, the film maker brings the story back around to Varlam's son, Avel, a man perhaps more insidious than his father because he can seem reasonable.
It called the election an "insidious maneuver by the racist minority regime of South Africa" that will "entrench white minority rule" and cause more conflict.
Many union, safety and academic experts say Kellen is an example of an insidious trend in American industry: Companies are producing more, cutting payrolls, modernizing, computerizing _ and creating a more hazardous workplace.
"I am outraged that my own country engages in such insidious police state tactics of keeping files on law-abiding organizations and people," Lindblom told reporters.
That can have a much more insidious effect on the organization than people estimate." The loss of the snack business is particularly frustrating for Levine Huntley because Frito-Lay insists it was happy with the agency's work.
Until the bond market levelled out (as it did in the middle of last week) there was little chance that the stock market would stabilise. This insidious cycle took everyone by surprise, from market analysts to regulators.