Definition of insidious
Examples of insidious in a Sentence
But the litigation is also prompting a subtle and insidious change in the way that medicine is practiced, which affects anyone who consults a health professional, even if they would not dream of setting foot in a lawyer's office. It is known as “defensive medicine.” —Geoff Watts, New Scientist, 23–29 Oct. 2004
Spin is sometimes dismissed as a simple euphemism for lying. But it's actually something more insidious: indifference to the truth. —Michael Kinsley, Time, 25 Dec. 2000–1 Jan. 2001
As these boats aged and bedding compounds deteriorated, the water torture began, which led to rot, corrosion, and other insidious problems. —Ralph Naranjo, Cruising World, April 1999
Most people with this insidious disease have no idea that they are infected.
Recent Examples of insidious from the Web
The virus, whose victims included major global companies from Merck & Co. to PAO Rosneft, bore similarities to last month’s global ransomware attack but was in some ways more insidious, security experts say.
There is an insidious, racially motived ideological belief, that black men in America need to be contained.
And it must be defended not merely from war or political calamity, but from that natural, more insidious phenomenon: forgetting.
One of the most insidious tools in CrashOverride manipulates the settings on electric power control systems.
There was the insidious practice of redlining by banks, and many city neighborhoods had racial-restrictive covenants.
Critics say gains in Big Data and artificial intelligence are more insidious in China than the West because China's political system offers far fewer protections for individual rights.
Beyond white people’s need to deny the racist history of the word is an insidious desire to be part of everything, whether it is meant for them or not.
This highlights the insidious nature of radicalization.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'insidious'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
insidious, sinister, or pernicious?
Few would choose to be associated with people or things that are insidious, sinister, or pernicious; all three of these words have decidedly unpleasant meanings, each with its own particular shade of nastiness.
Insidious comes from a Latin word for “ambush” (insidiae), which is fitting, as this word often carries the meanings “deceitful,” “stealthy,” or “harmful in an imperceptible fashion.” The first two meanings may be applied to people or things (“an insidious enemy,” “an insidious plot”), while the last is usually applied to things (“insidious problems,” “insidious sexism”), in particular to the gradual progress of a disease (“an insidious malignancy”).
Sinister comes from a Latin word meaning “on the left side, unlucky, inauspicious.” Although it is commonly used today in the sense “evil” (“a sinister cult leader”; “a sinister plot”), it may also suggest an ominous foreshadowing of some unfavorable turn of events (“a sinister omen”).
Pernicious has largely stayed true to its etymological root, the Latin noun pernicies “ruin, destruction.” Its original meaning in English, “highly injurious or destructive,” usually applies to things (“pernicious apathy,” “pernicious effects”) and medical conditions (“pernicious fever,” pernicious anemia). When applied to people, pernicious means “wicked.”
INSIDIOUS Defined for English Language Learners
Definition of insidious for English Language Learners
: causing harm in a way that is gradual or not easily noticed
Medical Definition of insidious
: developing so gradually as to be well established before becoming apparent an insidious disease
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