The abrupt stillness seemed alien and artificial, a little insidious.
It was like seditious and insidious too, and like socialist, suspicious, fascist and Communist.
Major Danby confided that Group was incensed with all flight surgeons because of Dr. Stubbs, the bushy-haired, baggy-chinned, slovenly flight surgeon in Dunbar’s squadron who was deliberately and defiantly brewing insidious dissension there by grounding all men with sixty missions on proper forms that were rejected by Group indignantly with orders restoring the confused pilots, navigators, bombardiers and gunners to combat duty.
There are no more uses of "insidious" in the book.
Show samples from other sources
The debt grew insidiously—just a little at a time and always for a good purpose.
Alan Greenspan -- The Age of Turbulence
We’ve grown accustomed to spending more than we earn, but the increasing debt is an insidious problem.