pernicious

[per-nish-uhs]

adjective

1. causing insidious harm or ruin; ruinous; injurious; hurtful.

   pernicious teachings;

   a pernicious lie.

   Synonyms: malicious, noxious, baneful, damaging, destructive, deleterious, detrimental, harmful

2. deadly; fatal.

   a pernicious disease.

   Synonyms: lethal

3. Obsolete.,  evil; wicked.

pernicious

/ pəˈnɪʃəs /

adjective

1. wicked or malicious

   pernicious lies

2. causing grave harm; deadly

Other Word Forms

• perniciously adverb
• perniciousness noun
• unpernicious adjective
• unperniciously adverb

Word History and Origins

Origin of pernicious¹

First recorded in 1515–25; from Latin perniciōsus “ruinous,” from pernici(ēs) “ruin” (from per- per- + -nici-, combining form of nex “death, murder” + -ēs, noun suffix) + -ōsus -ous

Word History and Origins

Origin of pernicious¹

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

Example Sentences

Stephen Miran, who became a Fed governor in September and is on leave as a White House adviser, co-wrote a paper last year saying more dissent would help combat “pernicious groupthink.”

Read more on The Wall Street Journal

The music stars urged the prime minister to stop the "extortionate and pernicious" websites that exploit fans.

Read more on BBC

The irony of the BBC is that it loves to tell people how influential it is without understanding that it is this very influence that is so pernicious.

Read more on The Wall Street Journal

For Mr Teltumbde, castes are "too pernicious to be managed for any progressive purpose".

Read more on BBC

In a 2005 speech, he called the Democrats who accused the administration of manipulating intelligence to justify the war “opportunists” who peddled “cynical and pernicious falsehoods” to gain political advantage.

Read more on Los Angeles Times

Related Words

• damaging 
• dangerous 
• deadly 
• destructive 
• detrimental 
• devastating 
• harmful 
• lethal 
• malicious 
• nefarious 
• noxious 
• poisonous 
• ruinous 
• toxic 
• virulent