PERNI'CIOUS, adjective [Latin perniciosus, from pernicies; perneco, to kill; per and nex, necis, death.]
1. Destructive; having the quality of killing, destroying or injuring; very injurious or mischievous. Food, drink or air may be pernicious to life or health.
2. Destructive; tending to injure or destroy. Evil examples are pernicious to morals. Intemperance is a pernicious vice.
3. [Latin pernix.] Quick. [Not used.]
PERNI'CIOUSLY, adverb Destructively; with ruinous tendency or effects.
PERNI'CIOUSNESS, noun The quality of being very injurious, mischievous or destructive.