Insidious meaning

ĭn-sĭdē-əs
The definition of insidious is something or someone who works in a subtle or sly way, or in an intent to trap.

An example of insidious is a plan that is meant to scam people out of money.

adjective
25
4
Producing harm in a stealthy, often gradual, manner.
adjective
19
1
Intending to entrap; alluring but harmful.

Hansel and Gretel were lured by the witch’s insidious gingerbread house.

adjective
16
1
Working or spreading harmfully in a subtle or stealthy manner.

Insidious rumors; an insidious disease.

adjective
13
2
Intended to entrap; treacherous.

Insidious misinformation.

adjective
12
1
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Characterized by treachery or slyness; crafty; wily.
adjective
5
0
Working harm in a slow or subtle manner; hence, more dangerous than seems evident.

An insidious disease.

adjective
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0
(nonstandard) Treacherous.

The battle was lost due to the actions of insidious defectors.

adjective
3
0
Beguiling but harmful; alluring.

Insidious pleasures.

adjective
2
0

Origin of insidious

  • From Latin īnsidiōsus from īnsidiae ambush from īnsidēre to sit upon, lie in wait for in- in, on in–2 sedēre to sit sed- in Indo-European roots

    From American Heritage Dictionary of the English Language, 5th Edition

  • From Middle French insidieux, from Latin īnsidiōsus (“cunning, artful, deceitful”), from īnsidiae (“a lying in wait, an ambush, artifice, stratagem”) + -ōsus, from īnsideō (“to sit in or on”), from in (“in, on”) + sedeō (“to sit”).

    From Wiktionary