pernicieux
French, adjective/pɛʁ.ni.sjø/
pernicieux is spelled P-E-R-N-I-C-I-E-U-X (10 letters) and appears about once in every 2 million words in written French, the 46,078th most frequent French word form (wordfreq, 2021 data). Pernicieux is a French adjective meaning “insidious (having a slow and discreet, but dangerous evolution)” (English Wiktionary, September 2026). The French Wiktionary (Wiktionnaire) defines it as “Qui est mauvais, dangereux, nuisible, préjudiciable, le plus souvent d’un point de vue moral ou social”.
What does pernicieux mean in English?
adjective
- 1
rareinsidious (having a slow and discreet, but dangerous evolution)
anémie pernicieuse
- 2
morally harmful; pernicious
- 3
datedliterally harmful or dangerous, usually of animals or persons
Source: English Wiktionary, French section, dump of September 2, 2026 (CC BY-SA 4.0).
How French dictionaries define it
adjective: 1. Qui est mauvais, dangereux, nuisible, préjudiciable, le plus souvent d’un point de vue moral ou social. 2. Se dit d’une maladie dont l’évolution conduit presque toujours à la mort du malade.
The definition in the French Wiktionary (Wiktionnaire), in French.
Source: French Wiktionary (Wiktionnaire), dump of September 1, 2026 (CC BY-SA 4.0), through kaikki.org.
Forms of pernicieux
- pernicieuse feminine
- pernicieuses feminine plural
Source: English Wiktionary and French Wiktionary (Wiktionnaire) (dumps of September 2, 2026 and September 1, 2026).
How do you pronounce pernicieux?
- /pɛʁ.ni.sjø/
- \pɛʁ.ni.sjø\
Sources: English Wiktionary, French Wiktionary (Wiktionnaire) (dumps of September 2, 2026 and September 1, 2026); recordings from Wikimedia Commons.
English words that translate to pernicieux
Source: the translation tables of the English Wiktionary, dump of September 2, 2026.
How common is pernicieux in French?
pernicieux appears about once in every 2 million words in written French.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).