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.
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Origin of insidious
OTHER WORDS FROM insidious
WORDS THAT MAY BE CONFUSED WITH insidious
insidious , invidiousDictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021
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
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