INSIDIOUSLY

insidiously, perniciously

(adverb) in a harmfully insidious manner; “these drugs act insidiously”

Source: WordNet® 3.1


Etymology

Adverb

insidiously (comparative more insidiously, superlative most insidiously)

in an insidious manner

Source: Wiktionary


INSIDIOUS

In*sid"i*ous, a. Etym: [L. insidiosus, fr. insidiae an ambush, fr. insidere to sit in; pref. in- + sedere to sit: cf. F. insidieux. See Sit.]

1. Lying in wait; watching an opportunity to insnare or entrap; deceitful; sly; treacherous; -- said of persons; as, the insidious foe. "The insidious witch." Cowper.

2. Intended to entrap; characterized by treachery and deceit; as, insidious arts. The insidious whisper of the bad angel. Hawthorne. Insidious disease (Med.), a disease existing, without marked symptoms, but ready to become active upon some slight occasion; a disease not appearing to be as bad as it really is.

Syn.

– Crafty; wily; artful; sly; designing; guileful; circumventive; treacherous; deceitful; deceptive.

– In*sid"i*ous*ly, adv.

– In*sid"i*ous*ness, n.

Source: Webster’s Unabridged Dictionary 1913 Edition



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Word of the Day

20 April 2025

SALAD

(noun) food mixtures either arranged on a plate or tossed and served with a moist dressing; usually consisting of or including greens


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Coffee Trivia

According to Guinness World Records, on 25 September 2016, the Birla Institute of Management Technology (India) in Uttar Pradesh, India, constructed the largest coffee cups pyramid consisting of 23,821 cups. They used paper takeaway coffee cups to build the pyramid.

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