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Definition of insidiously

insidiously

/ɪnˈsɪd.i.əs.li/
in · sid · i · ous · ly
Adjective:insidious
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insidiously Lexical Profile

insidiously Game Scores & Validity

• adverb

1

In a gradual, subtle, or stealthy way, but with harmful or destructive effects.

Example

"The disease progresses insidiously, often causing severe damage before any symptoms are noticed."

2

In a treacherous, deceitful, or crafty manner intended to entrap or beguile.

Example

"Rumors were insidiously spread throughout the organization to undermine the director's authority."

Synonyms
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Antonyms
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• Rhymes for insidiously

• Nearby Words

insider
insidery
insidious
insidiously
insight
insightful
insightfully

Word Origin & Etymology

Formed from the adjective 'insidious' plus the adverbial suffix '-ly'. 'Insidious' comes from the Latin 'insidiosus' ('cunning, deceitful'), derived from 'insidiae' ('ambush, plot'), from 'insidere' ('to sit in or wait for').

Cite this Entry

Wordmom. (2026). Definition of Insidiously. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/insidiously
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