Here are some ways to understand "insidiously":
* Slowly and stealthily: Like a disease that spreads slowly and silently, an insidious problem can take root and grow before it becomes apparent.
* Deceptively harmful: Something insidious may seem harmless at first, but it can have serious consequences in the long run.
* Evolving and persistent: Insidious problems often continue to worsen over time and are difficult to eradicate.
Examples:
* "The virus spreads insidiously, often showing no symptoms in the early stages."
* "The rumors about the scandal were spread insidiously, slowly eroding public trust in the company."
* "The insidious effects of stress can lead to serious health problems."
Synonyms:
* Deviously
* Treacherously
* Clandestinely
* Underhandedly
* Perfidiously
Antonyms:
* Openly
* Obviously
* Directly
* Honestly