the investigators uncovered an insidious scheme to rob people of their money
Morrie's disease "ALS" is insidious .
Insidious means deceitful and cunning. You could use it in a sentence such as "His insidious plan to take over the world might actually work".
Facetious or insidious
Plagiarism is an insidious habit.
Insidious
The insidious spread of misinformation on social media has led to confusion and division among the population.
Another word for "insidious" is the word "treacherous"[or "sly",or "crafty"].
The investigators uncovered an insidious scheme to rob people of their life savings. Another one is "There is a more insidious threats to Gulf stability."
The insidious nature of the virus allowed it to spread undetected throughout the community.
You divide it like this: in-si-di-ous.
The insidious wickedness of the witch was ably portrayed.
what is a good sentence for the word opposite