adj.
- Tending to cause death or serious injury; deadly: a pernicious virus.
- Causing great harm; destructive: pernicious rumors.
- Archaic. Evil; wicked.
[Middle English, from Old French pernicios, from Latin perniciōsus, from perniciēs, destruction : per-, per- + nex, nec-, violent death.]
perniciously per·ni'cious·ly adv.perniciousness per·ni'cious·ness n.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
