Advertisement

Advertisement

View synonyms for insidious

insidious

[ in-sid-ee-uhs ]

adjective

  1. intended to entrap or beguile:

    an insidious plan.

  2. stealthily treacherous or deceitful:

    an insidious enemy.

    Synonyms: crafty, subtle, wily, cunning, artful

  3. operating or proceeding in an inconspicuous or seemingly harmless way but actually with grave effect:

    an insidious disease.



insidious

/ ɪnˈsɪdɪəs /

adjective

  1. stealthy, subtle, cunning, or treacherous
  2. working in a subtle or apparently innocuous way, but nevertheless deadly

    an insidious illness

“Collins English Dictionary — Complete & Unabridged” 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012


Discover More

Derived Forms

  • inˈsidiousness, noun
  • inˈsidiously, adverb
Discover More

Other Words From

  • in·sidi·ous·ly adverb
  • in·sidi·ous·ness noun
  • unin·sidi·ous adjective
  • unin·sidi·ous·ly adverb
  • unin·sidi·ous·ness noun
Discover More

Word History and Origins

Origin of insidious1

First recorded in 1535–45; from Latin insidiōsus “deceitful,” from insidi(ae) (plural) “an ambush” (from insidēre “to sit in”) + -ōsus -ous; sit 1
Discover More

Word History and Origins

Origin of insidious1

C16: from Latin insidiōsus cunning, from insidiae an ambush, from insidēre to sit in; see insessorial
Discover More

Example Sentences

But what’s even more insidious is that when Trump and other right-wing speakers invoke the “threat” posed by dark-skinned immigrants, he’s tapping into many white men’s sense of themselves as protectors.

From Salon

The success of these and other measures will rely on a well-staffed EPA enforcement division, which may end up being one of the most insidious stakes of this election for environmental policies.

From Salon

Breed’s supporters stand by her, hailing her as a homegrown champion who has led the city during a period of crisis that included a global pandemic and the insidious rise of fentanyl.

The Republican ticket returned to this insidious and unfounded accusation at the second Butler rally.

From Salon

The full story of the insidious relationship between the state and the cartels in Guerrero - and its part in the students’ abduction - has never been fully established.

From BBC

Advertisement

Related Words

Discover More

More About Insidious

What does insidious mean?

Insidious describes something as being sneaky or being secretly dangerous or harmful.

Insidious also describes something as being corrupting or intending to entrap.

The word insidious is used to describe something as being stealthy, treacherous, or operating in the shadows, as in He came up with an insidious plan to rob the jewelry store. Insidious is always associated with something negative, implying something is bad or is going to cause harm.

Insidious is also often used to describe something as appearing harmless or nonthreatening but subtly causing serious damage, as in The insidious language in the book radicalized many readers without them even knowing it.

Related to this sense, insidious is used in medicine to refer to diseases that slowly get worse and worse without any noticeable signs that they are there at all. Cancer is often described as insidious because it is often found when it is too late to treat it.

Example: The investigators were after an insidious group of hackers who were stealing government secrets.

Where does insidious come from?

The first records of insidious come from around 1535. It comes from the Latin insidiōsus, meaning “deceitful.”

The word insidious is often used in the media and popular culture to describe conspiracies, schemes, corruption, shadowy organizations, and other bad things that are done in secret.

Did you know ... ?

What are some other forms related to insidious?

  • insidiously (adjective)
  • insidiousness (noun)

What are some synonyms for insidious?

What are some words that often get used in discussing insidious?

How is insidious used in real life?

Insidious is a word that describes something as being sneaky and up to no good.

Try using insidious!

Is insidious used correctly in the following sentence?

She was so cunning and crafty that we didn’t have a clue about her insidious plans until after she had betrayed us.

Advertisement

Advertisement

Advertisement


inside voiceinsight