from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Tending to cause death or serious injury; deadly: a pernicious virus.
- adj. Causing great harm; destructive: pernicious rumors.
- adj. Archaic Evil; wicked.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Causing much harm in a subtle way.
- adj. Causing death or injury; deadly.
from the GNU version of the Collaborative International Dictionary of English
- adj. Quick; swift (to burn).
- adj. Having the quality of injuring or killing; destructive; very mischievous; baleful; malicious; wicked.
from The Century Dictionary and Cyclopedia
- Having the property of destroying or being injurious; hurtful; destructive.
- Wicked; malicious; evil-hearted.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. exceedingly harmful
- adj. working or spreading in a hidden and usually injurious way
Middle English, from Old French pernicios, from Latin perniciōsus, from perniciēs, destruction : per-, per- + nex, nec-, violent death; see nek-1 in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Middle English, from Old French pernicios, from Latin perniciosus ("destructive"), from pernicies ("destruction"), from per ("through") + nex ("slaughter, death") (Wiktionary)