insidious
[ in-sid-ee-uhs ]
/ ɪnˈsɪd i əs /
adjective
intended to entrap or beguile: an insidious plan.
stealthily treacherous or deceitful: an insidious enemy.
operating or proceeding in an inconspicuous or seemingly harmless way but actually with grave effect: an insidious disease.
QUIZZES
Can You Ace This Quiz About “Compliment” vs. “Complement”?
Take this quiz to see if you really know the difference between “compliment” and “complement"!
Question 1 of 11
“Compliment” and “complement” had a shared meaning a long time ago, but today they are no longer interchangeable.
Origin of insidious
OTHER WORDS FROM insidious
WORDS THAT MAY BE CONFUSED WITH insidious
insidious invidiousWords nearby insidious
inside track, inside track, the, insider, insider dealing, insider trading, insidious, insight, insightful, insigne, insignia, insignificance
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020
Example sentences from the Web for insidious
British Dictionary definitions for insidious
insidious
/ (ɪnˈsɪdɪəs) /
adjective
stealthy, subtle, cunning, or treacherous
working in a subtle or apparently innocuous way, but nevertheless deadlyan insidious illness
Derived forms of insidious
insidiously, adverbinsidiousness, nounWord Origin for insidious
C16: from Latin insidiōsus cunning, from insidiae an ambush, from insidēre to sit in; see insessorial
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Medical definitions for insidious
insidious
[ ĭn-sĭd′ē-əs ]
adj.
Being a disease that progresses with few or no symptoms to indicate its gravity.
Other words from insidious
in•sid′i•ous•ly adv.The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.