Insidious is used to describe something or someone who is purposeful and clever in their treachery or harmful plans. An example sentence might be: Sarah insidiously started a rumor about Jacob, knowing it would eventually be the talk of the school.
The insidious disease seemed like just a harmless cold at first, but then killed its victims in the end.
Plagiarism is an insidious habit.
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".
the investigators uncovered an insidious scheme to rob people of their money
I've been to several specialists and no one can cure this insidious rash.
The book's summary revealed the main character's insidious plot to obtain the large inheritance, illegally.
The insidious wickedness of the witch was ably portrayed.
Facetious or insidious
The kindness of a con man is an insidious ploy to gain the trust of his victims.
insidious
Insidious is an adjective.
Insidious