Also found in: Thesaurus, Medical, Wikipedia.


1. Tending to cause death or serious injury; deadly: a pernicious virus.
2. Causing great harm; destructive: pernicious rumors.

[Middle English, from Old French pernicios, from Latin perniciōsus, from perniciēs, destruction : per-, per- + nex, nec-, violent death; see nek- in Indo-European roots.]

per·ni′cious·ly adv.
per·ni′cious·ness n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.perniciousness - grave harmfulness or deadlinessperniciousness - grave harmfulness or deadliness  
unwholesomeness, morbidness, morbidity - the quality of being unhealthful and generally bad for you
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
(188) The perniciousness of the legislation, however, laid bare that the Court's prior decisions had trapped it in an understanding of public education with troubling implications.
Dubin's Lives came out almost two decades after Rachel Carson's seminal works on ocean water as the omphalos of all life and on the perniciousness of pesticides had already made their indelible indent into global consciousness.
Until then there is nothing to do but to wait things out, in the hope that the deep illogic of political correctness and its widespread perniciousness, like that of Prohibition and other programs of enforced virtue that have gone before, will indubitably reveal itself for the grievous mistake it is.
With the horrors of pork barrel continuing to inflict themselves upon us, almost helpless citizens, let us recall what happened in 2013, the year the pork barrel abuses were revealed to the public in all its monstrous perniciousness.
The perniciousness of the vision can be found in its organizing principle of unlimited growth.
If one recommends policy changes based on a detrimental economy-wide impact, one should bring forward evidence of its economy-wide presence, power, and perniciousness. Not only has this not been done, but the broad evidence points to the contrary.
(Davis, 2018) The perniciousness of sexual harassment, exploitation, and aggression does not fall uniformly on men and on women.
However, considering that this fight will be extremely hampered by inertia of the population, its political passivity and lack of knowledge, the "Yedinstvo" put propaganda activities among the working masses, one of its main tasks--explaining to them the perniciousness of the victory of the German imperialism for Russia, discovery of the role played by the Bolshevik government in successes of this imperialism and in the all-Russian collapse, and also awakening among the masses of sympathy for the Entente.
In their recently released book, Everyday Communalism: Riots in Contemporary Uttar Pradesh, two political scientists from New Delhi's Jawaharlal Nehru University, Sudhai Pai and Sajjan Kumar, detail the perniciousness of the new strategy of communalisation, based on 'using small, mundane but provocative local incidents to gradually create animosity and social jealousies between Hindus and Muslims who have lived together for a long time'.