- Insidious
- Insidious In*sid"i*ous, a. [L. insidiosus, fr. insidiae an
ambush, fr. insidere to sit in; pref. in- + sedere to sit:
cf. F. insidieux. See {Sit}.]
[1913 Webster]
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.
[1913 Webster]
2. Intended to entrap; characterized by treachery and deceit; as, insidious arts. [1913 Webster]
The insidious whisper of the bad angel. --Hawthorne. [1913 Webster]
3. Acting or proceeding unobserved or in a seemingly harmless manner, but slowly or eventually doing great damage; as, an insidious disease; an insidious plot. [PJC]
{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. [1913 Webster]
The Collaborative International Dictionary of English. 2000.