pernicialis

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

pernĭcĭālis, e, adj. [pernicies],

destructive , deadly , fatal : discidium, Lucr. 1, 451: morbi, Liv. 27, 23: proelia, Plin. 8, 5, 5, § 13.