Dictionary
Thesaurus
Reference
Translate
Web
Related Searches
on Ask.com
Synonyms
Nearby Entries
insidious - 6 dictionary results

in⋅sid⋅i⋅ous

  [in-sid-ee-uhs]
Use insidious in a Sentence
–adjective
1. intended to entrap or beguile: an insidious plan.
2. stealthily treacherous or deceitful: an insidious enemy.
3. operating or proceeding in an inconspicuous or seemingly harmless way but actually with grave effect: an insidious disease.
Origin:
1535–45; < L insidiōsus deceitful, equiv. to insidi(ae) (pl.) an ambush (deriv. of insidēre to sit in or on) + -ōsus -ous

Related forms:
in⋅sid⋅i⋅ous⋅ly, adverb
in⋅sid⋅i⋅ous⋅ness, noun

Synonyms:
1. corrupting. 2. artful, cunning, wily, subtle, crafty.
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source Link To insidious
in·sid·i·ous   (ĭn-sĭd'ē-əs)   
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 īnsidiōsus, from īnsidiae, ambush, from īnsidēre, to sit upon, lie in wait for : in-, in, on; see in-2 + sedēre, to sit; see sed- in Indo-European roots.]
in·sid'i·ous·ly adv., in·sid'i·ous·ness n.
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2009 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source

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.]

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.
Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.
Cite This Source

insidious 
1545, from L. insidiosus "deceitful," from insidiæ (pl.) "plot, snare, ambush," from insidere "sit on, occupy," from in- "in" + sedere "to sit" (see sedentary).
Online Etymology Dictionary, © 2001 Douglas Harper
Cite This Source

Main Entry: in·sid·i·ous
Pronunciation: in-'sid-E-&s
Function: adjective
: developing so gradually as to be well established beforebecoming apparent insidious disease> —in·sid·i·ous·ly adverb
Merriam-Webster's Medical Dictionary, © 2002 Merriam-Webster, Inc.
Cite This Source

insidious in·sid·i·ous (ĭn-sĭd'ē-əs)
adj.
Being a disease that progresses with few or no symptoms to indicate its gravity.

in·sid'i·ous·ly adv.
in·sid'i·ous·ness n.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
Search another word or see insidious on Thesaurus | Reference