Search Result for "perniciousness": 
Wordnet 3.0

NOUN (1)

1. grave harmfulness or deadliness;
[syn: perniciousness, toxicity]

The Collaborative International Dictionary of English v.0.48:

Pernicious \Per*ni"cious\, a. [L. perniciosus, from pernicies destruction, from pernecare to kill or slay outright; per + necare to kill, slay: cf. F. pernicieux. Cf. Nuisance, Necromancy.] Having the quality of injuring or killing; destructive; very mischievous; baleful; malicious; wicked. [1913 Webster] Let this pernicious hour Stand aye accursed in the calendar. --Shak. [1913 Webster] Pernicious to his health. --Prescott. [1913 Webster] Syn: Destructive; ruinous; deadly; noxious; injurious; baneful; deleterious; hurtful; mischievous. [1913 Webster] -- Per*ni"cious*ly, adv., -- Per*ni"cious*ness, n. [1913 Webster]
WordNet (r) 3.0 (2006):

perniciousness n 1: grave harmfulness or deadliness [syn: perniciousness, toxicity]