Destructive; harmful; denoting a disease of severe character and usually fatal without appropriate treatment. [L. perniciosus, destructive, fr. pernicies, destruction]
* * *
per·ni·cious pər-'nish-əs adj highly injurious or destructive: tending to a fatal issue: DEADLY <\pernicious disease>
* * *
adj.
describing diseases that are highly dangerous or likely to result in death if untreated. See also pernicious anaemia.
* * *
per·ni·cious (pər-nishґəs) [L. perniciosus] harmful; tending toward a fatal outcome.Medical dictionary. 2011.