Dictionary.com
definitions
  • synonyms

pernicious

[per-nish-uh s]
See more synonyms on Thesaurus.com
adjective
  1. causing insidious harm or ruin; ruinous; injurious; hurtful: pernicious teachings; a pernicious lie.
  2. deadly; fatal: a pernicious disease.
  3. Obsolete. evil; wicked.

Origin of pernicious

1515–25; < Latin perniciōsus ruinous, equivalent to pernici(ēs) ruin (per- per- + -nici-, combining form of nex death, murder (stem nec-) + -iēs noun suffix) + -ōsus -ous
Related formsper·ni·cious·ly, adverbper·ni·cious·ness, nounun·per·ni·cious, adjectiveun·per·ni·cious·ly, adverb

Synonyms

See more synonyms on Thesaurus.com
1. harmful, detrimental, deleterious, destructive, damaging, baneful, noxious, malicious. 2. lethal.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for pernicious

Contemporary Examples

Historical Examples


British Dictionary definitions for pernicious

pernicious

adjective
  1. wicked or maliciouspernicious lies
  2. causing grave harm; deadly
Derived Formsperniciously, adverbperniciousness, noun

Word Origin

C16: from Latin perniciōsus, from perniciēs ruin, from per- (intensive) + nex death
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

Word Origin and History for pernicious

adj.

early 15c., from Middle French pernicios (13c., Modern French pernicieux) and directly from Latin perniciosus "destructive," from pernicies "destruction, death, ruin," from per- "completely" (see per) + necis "violent death, murder," related to necare "to kill," nocere "to hurt, injure, harm," noxa "harm, injury" (see noxious). Related: Perniciously; perniciousness.

Online Etymology Dictionary, © 2010 Douglas Harper

pernicious in Medicine

pernicious

(pər-nĭshəs)
adj.
  1. Tending to cause death or serious injury; deadly.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.