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
Insidious
Plagiarism is an insidious habit.
I've been to several specialists and no one can cure this insidious rash.
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 book's summary revealed the main character's insidious plot to obtain the large inheritance, illegally.
You divide it like this: in-si-di-ous.
what is a good sentence for the word opposite
The insidious wickedness of the witch was ably portrayed.