- causing insidious harm or ruin; ruinous; injurious; hurtful: pernicious teachings; a pernicious lie.
- deadly; fatal: a pernicious disease.
- Obsolete. evil; wicked.
Origin of pernicious
SynonymsSee more synonyms for pernicious on Thesaurus.com
Examples from the Web for pernicious
Cancer is the most pernicious, insidious, disgusting disease of life.Pierce Brosnan’s Life After Bond: From Action Hero to Losing His Daughter to Cancer
July 2, 2014
I spoke to my students about mobilizing against this pernicious threat to our civilization.As Parents We’re All Gun Violence Cowards
May 30, 2014
The nature of the harm allegedly caused by Goddard was “subtle, imperceptible and pernicious.”Exclusive: Bryan Singer Faces New Teen Sex Assault Lawsuit
May 4, 2014
“There is a pernicious effect of money on the legislative process,” he argued.Congress Can Be Corrupt Without Corrupt People
December 13, 2013
The biggest problem is not that such unfounded theories are ludicrous but that they are pernicious.Who Really Killed JFK? Experts Pick the Wildest Conspiracy Theories
November 20, 2013
Perhaps it is in this last that it becomes our most pernicious enemy.The Conquest of Fear
He said this was to discourage that pernicious class of men, the inventors.
Pride is excellent; but even pride may sometimes be pernicious.The Boy Life of Napoleon
But forego, if possible, your pernicious stimulant of laudanum.The Works of Whittier, Volume V (of VII)
John Greenleaf Whittier
All books which meddle with the faith are condemnable and pernicious.The Three Cities Trilogy, Complete
- wicked or maliciouspernicious lies
- causing grave harm; deadly
Word Origin and History for pernicious
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.
- Tending to cause death or serious injury; deadly.