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GRE vocabulary

insidious

adjectiveHigh-frequency wordMore I words

proceeding in a gradual, harmful way that is hard to detect

Word origin: From Latin insidiae, ambush, from insidere, to sit in wait.

In a sentence

Insidious in a sentence

Here are example sentences showing insidious in a sentence.

The disease is insidious, causing irreversible damage before symptoms appear.

The corrosion was insidious, advancing unseen within the pipes until the structure suddenly failed.

Antonyms
obviousharmless
Usage & nuance

Using “insidious” well

Insidious stresses harm that develops gradually and stealthily, so its danger is hidden until too late, which sets it against obvious and harmless.

Common questions

Questions about “insidious

Insidious (adjective) means proceeding in a gradual, harmful way that is hard to detect
Here is insidious used in an example sentence: "The disease is insidious, causing irreversible damage before symptoms appear." Another example: "The corrosion was insidious, advancing unseen within the pipes until the structure suddenly failed."
Common synonyms for insidious include stealthy, treacherous, subtle, sneaky.
Antonyms of insidious include obvious, harmless.
Insidious clusters with stealthy, treacherous, subtle, and sneaky. Its antonyms obvious and harmless mark the contrast; do not confuse it with invidious.
Yes. Insidious is a high-frequency GRE word, so it is worth prioritising as you build your vocabulary.

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