It was observed that even medical families cannot escape the more insidious forms of disease, and that, after all, Dr. Sloper had lost other patients beside the two I have mentioned; which constituted an honourable precedent.
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.