What does insidious mean?

Definitions for insidious
ɪnˈsɪd i əsin·sid·i·ous

This dictionary definitions page includes all the possible meanings, example usage and translations of the word insidious.

Princeton's WordNet

  1. insidiousadjective

    beguiling but harmful

    "insidious pleasures"

  2. insidiousadjective

    intended to entrap

  3. insidious, pernicious, subtleadjective

    working or spreading in a hidden and usually injurious way

    "glaucoma is an insidious disease"; "a subtle poison"


  1. Insidiousadjective

    Acting or proceeding unobserved or in a seemingly harmless manner, but slowly or eventually doing great damage; as, an insidious disease; an insidious plot.


  1. insidiousadjective

    Producing harm in a stealthy, often gradual, manner.

  2. insidiousadjective

    Intending to entrap; alluring but harmful

  3. insidiousadjective


  4. Etymology: From insidiosus, from insidiae + -osus, from insideo, from in + sedeo.

Samuel Johnson's Dictionary

  1. INSIDIOUSadjective

    Sly; circumventive; diligent to entrap; treacherous.

    Etymology: insidieux, French; insidiosus, Latin.

    Since men mark all our steps, and watch our haltings, let a sense of their insidious vigilance excite us so to behave ourselves, that they may find a conviction of the mighty power of Christianity towards regulating the passions. Francis Atterbury, Sermons.

    They wing their course,
    And dart on distant coasts, if some sharp rock,
    Or shoal insidious, breaks not their career. James Thomson.

Webster Dictionary

  1. Insidiousadjective

    lying in wait; watching an opportunity to insnare or entrap; deceitful; sly; treacherous; -- said of persons; as, the insidious foe

  2. Insidiousadjective

    intended to entrap; characterized by treachery and deceit; as, insidious arts

  3. Etymology: [L. insidiosus, fr. insidiae an ambush, fr. insidere to sit in; pref. in- + sedere to sit: cf. F. insidieux. See Sit.]


  1. Insidious

    Insidious is the 5th full-length album by Mephisto Walz. All the tracks on this album were arranged, recorded, mixed, written and produced by Barry Galvin. Christianna provided the vocals and David Glass supplied some of the drums for this album.

Chambers 20th Century Dictionary

  1. Insidious

    in-sid′i-us, adj. watching an opportunity to ensnare: intended to entrap: deceptive: advancing imperceptibly: treacherous.—adv. Insid′iously.—n. Insid′iousness. [L. insidiosusinsidiæ, an ambush—insidērein, sedēre, to sit.]

Suggested Resources

  1. insidious

    Song lyrics by insidious -- Explore a large variety of song lyrics performed by insidious on the Lyrics.com website.

How to pronounce insidious?

How to say insidious in sign language?


  1. Chaldean Numerology

    The numerical value of insidious in Chaldean Numerology is: 4

  2. Pythagorean Numerology

    The numerical value of insidious in Pythagorean Numerology is: 2

Examples of insidious in a Sentence

  1. Matthys Levy:

    Once deterioration like this starts, it's insidious, it just continues. Unless you do something about Champlain Towers South engineering firm, the whole thing is going to fall apart, all of the concrete is going to fall apart.

  2. James Stewart:

    Fear is an insidious and deadly thing. It can warp judgment, freeze reflexes, breed mistakes. Worse, it's contagious.

  3. Louis D. Brandeis:

    Experience should teach us to be most on our guard to protect liberty when the government's purposes are beneficial. The greatest dangers to liberty lurk in insidious encroachment by men of zeal, well meaning but without understanding.

  4. Louis Penner:

    The insidious thing about implicit racial bias is that it occurs among physicians who believe they're not racist, but patients pick up on it and (it) affects how they feel about the treatment.

  5. Lucius Annaeus Seneca:

    Conversation has a kind of charm about it, an insuating and insidious something that elicits secrets from us just like love or liquor.

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Translations for insidious

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"insidious." Definitions.net. STANDS4 LLC, 2023. Web. 28 May 2023. <https://www.definitions.net/definition/insidious>.

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    occurring from time to time
    • A. urban
    • B. occasional
    • C. nasty
    • D. brilliant

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