pernicious /pərˈniSHəs/ I. adjective having a harmful effect, especially in a gradual or subtle way • the pernicious influences of the mass media. II. derivatives 1. perniciously /pərˈniSHəslē / adverb 2. perniciousness /pərˈniSHəsnəs / noun – origin late Middle English: from Latin perniciosus ‘destructive,’ from pernicies ‘ruin,’ based on nex, nec- ‘death.’
