Pernicious /(?)/

Per·ni·cious

Pernicious

a.
  1. Quick; swift (to burn). [R.]

Pernicious

a.
  1. Having the quality of injuring or killing; destructive; very mischievous; baleful; malicious; wicked.
    Let this pernicious hour Stand aye accursed in the calendar.
    Pernicious to his health.