adj · 6 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
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Received-Pronunciation:/pəˈnɪʃəs/
General-American:/pɚˈnɪʃəs/
US:Recorded audio is listed in the source snapshot.
rhymes with -ɪʃəs
CMU ARPABET:P ER0 N IH1 SH AH0 S
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
adj
Meaning 1
Causing much harm in a subtle way.
Definition source: English Wiktionary via Wiktextract
Examples
pernicious influence
pernicious effects
They warned of the pernicious effects of misinformation.
The weed has a pernicious influence on local crops.
Meaning relationships
Synonyms: deleterious, venom
Antonyms: none provided
2
adj
Meaning 2
Causing death or injury; deadly.
Definition source: English Wiktionary via Wiktextract
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: attery
Antonyms: none provided
3
adj
Meaning 3
Insidiously villainous: intending to cause harm, especially in a subtle way.
Definition source: English Wiktionary via Wiktextract
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
4
adj
Meaning 4
swift; celeritous.
Definition source: English Wiktionary via Wiktextract
Usage: obsolete
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
5
adjective satellite
Meaning 5
working or spreading in a hidden and usually injurious way
Definition source: Princeton WordNet 3.0
Examples
glaucoma is an insidious disease
a subtle poison
Meaning relationships
Synonyms: insidious, subtle
Antonyms: none provided
6
adjective satellite
Meaning 6
exceedingly harmful
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: baneful, deadly, pestilent
Antonyms: none provided
History
Etymology
From Middle English, from Old French pernicios, from Latin perniciōsus (“destructive”), from perniciēs (“destruction”), from per (“through”) + nex (“slaughter, death”).
Analyzable as pernīx ("swift") + -ious.
Across languages
Translations
78 source translations are retained for this English entry.
Bulgarian:
па́губен
(páguben)
— causing much harm
Chinese Mandarin:
有害
(yǒuhài)
— causing much harm
Dutch:
schadelijk
— causing much harm
Dutch:
destructief
— causing much harm
Dutch:
verderfelijk
— causing much harm
Finnish:
turmiollinen
— causing much harm
Finnish:
haitallinen
— causing much harm
Finnish:
tuhoisa
— causing much harm
French:
nocif
— causing much harm
French:
malsain
— causing much harm
French:
pernicieux
— causing much harm
Georgian:
მავნე
(mavne)
— causing much harm
Georgian:
მავნებელი
(mavnebeli)
— causing much harm
Georgian:
საზიანო
(saziano)
— causing much harm
Georgian:
მაწყინარი
(mac̣q̇inari)
— causing much harm
German:
schädlich
— causing much harm
German:
bösartig
— causing much harm
German:
verderblich
— causing much harm
German:
perniziös
— causing much harm
Greek:
ολέθριος
(oléthrios)
— causing much harm
Hindi:
नाशक
(nāśak)
— causing much harm
Hungarian:
ártalmas
— causing much harm
Italian:
pernicioso
— causing much harm
Japanese:
有害な
(yūkai na)
— causing much harm
Latin:
perniciosus
— causing much harm
Macedonian:
погубен
(poguben)
— causing much harm
Norwegian Bokmål:
fordervelig
— causing much harm
Polish:
groźny
— causing much harm
Polish:
szkodliwy
— causing much harm
Polish:
zgubny
— causing much harm
Portuguese:
pernicioso
— causing much harm
Romanian:
pernicios
— causing much harm
Romanian:
vătămător
— causing much harm
Romanian:
dăunător
— causing much harm
Russian:
тлетво́рный
(tletvórnyj)
— causing much harm
Russian:
па́губный
(págubnyj)
— causing much harm
Russian:
зловредный
(zlovrednyj)
— causing much harm
Scottish Gaelic:
sgriosail
— causing much harm
Serbo-Croatian:
štetan
— causing much harm
Spanish:
pernicioso
— causing much harm
Swedish:
fördärvlig
— causing much harm
Turkish:
habis
— causing much harm
Turkish:
muzır
— causing much harm
Turkish:
pernisiyöz
— causing much harm
Turkish:
zararlı
— causing much harm
Ukrainian:
згубний
(zhubnyj)
— causing much harm
Ukrainian:
шкідливий
(škidlyvyj)
— causing much harm
Bulgarian:
ги́белен
(gíbelen)
— causing death or injury
Bulgarian:
па́губен
(páguben)
— causing death or injury
Chinese Mandarin:
致命
(zhìmìng)
— causing death or injury
Dutch:
dodelijk
— causing death or injury
Dutch:
schadelijk
— causing death or injury
Finnish:
tappava
— causing death or injury
French:
nocif
— causing death or injury
French:
délétère
— causing death or injury
French:
nuisible
— causing death or injury
French:
dangereux
— causing death or injury
German:
perniziös
— causing death or injury
German:
tödlich
— causing death or injury
Greek:
ολέθριος
(oléthrios)
— causing death or injury
Greek:
θανατηφόρος
(thanatifóros)
— causing death or injury
Hindi:
नाशक
(nāśak)
— causing death or injury
Hungarian:
veszedelmes
— causing death or injury
Japanese:
致命的な
(chimeiteki na)
— causing death or injury
Macedonian:
погубен
(poguben)
— causing death or injury
Māori:
whakawhara
— causing death or injury
Māori:
whakamōrearea
— causing death or injury
Polish:
zgubny
— causing death or injury
Portuguese:
mórbido
— causing death or injury
Romanian:
pernicios
— causing death or injury
Romanian:
vătămător
— causing death or injury
Romanian:
dăunător
— causing death or injury
Russian:
вре́дный
(vrédnyj)
— causing death or injury
Russian:
ги́бельный
(gíbelʹnyj)
— causing death or injury