insidious

in·sid·i·ous  (n-sd-s)

adj.

1. Working or spreading harmfully in a subtle or stealthy manner: insidious rumors; an insidious disease.

2. Intended to entrap; treacherous: insidious misinformation.

3. Beguiling but harmful; alluring: insidious pleasures.

---

[From Latin nsidisus, from nsidiae, ambush, from nsidre, to sit upon, lie in wait for : in-, in, on; see in-² + sedre, to sit; see sed- in Indo-European roots.]

---

in·sidi·ous·ly adv.

in·sidi·ous·ness n.

---

insidious

Adjective

working in a subtle or apparently harmless way, but nevertheless dangerous or deadly: an insidious virus [Latin insidiae an ambush]

insidiously adv
insidiousness n

Thesaurus

Adj.	1.	insidious - beguiling but harmful; "insidious pleasures" seductive - tending to entice into a desired action or state
	2.	insidious - intended to entrap dangerous, unsafe - involving or causing danger or risk; liable to hurt or harm; "a dangerous criminal"; "a dangerous bridge"; "unemployment reached dangerous proportions"
	3.	insidious - working or spreading in a hidden and usually injurious way; "glaucoma is an insidious disease"; "a subtle poison" pernicious, subtle harmful - causing or capable of causing harm; "too much sun is harmful to the skin"; "harmful effects of smoking"

---

insidious

adjective stealthy, subtle, cunning, designing, smooth, tricky, crooked, sneaking, slick, sly, treacherous, deceptive, wily, crafty, artful, disingenuous, Machiavellian, deceitful, surreptitious, duplicitous, guileful << OPPOSITE straightforward

Translations

insidious [ɪnˈsɪdɪəs] adj → insidioso

insidious [ɪnˈsɪdɪəs] adj → insidieux/euse

insidious [ɪnˈsɪdɪəs] adj → heimtückisch

insidious [ɪnˈsɪdɪəs] adj → insidioso/a