Lewis & Short

pernĭcĭes, ēi (old form of the gen. pernicii or pernici, Sisenn. ap. Gell. 9, 14, 12, and ap. Non. 486, 30; Cic. Rosc. Am. 45, 131, acc. to Gell. 9, 14, 19, and acc. to Non. 486, 28. But Charis., p. 53 P., gives for the passages of Cicero above cited the form pernicies; cf., also, Diom. p. 281 P.
Dat. pernicie, Liv. 5, 13, 5 Drak. N. cr.: pernicii, Nep. 8, 2; v. also, permities), f. [perneco], destruction, death, ruin, overthrow, disaster, calamity (syn.: exitium, labes).

  1. I. Lit.: quantā in pernicie siet, Plaut. Bacch. 4, 7, 29: de pernicie populi Romani et exitio hujus urbis, Cic. Cat. 4, 5, 10: videbam perniciem meam cum magnā calamitate rei publicae esse conjunctam, id. ib. 1, 5, 11: perniciem rei publicae moliens, id. ib. 1, 2, 5: cum tuā peste ac pernicie cumque eorum exitio, qui, etc., id. ib. 1, 13, 33: incumbere ad perniciem alicujus, id. Mur. 28, 59: in apertam perniciem incurrere, id. N. D. 3, 27, 69: ad perniciem vocari, id. de Or. 2, 9, 35: Romanos inferendae pernicii causā venisse, Sisenn. ap. Gell. and Non. 1. 1.: alicui perniciem machinari, Sall. C. 18, 7: perniciem invenire sibi et aliis, Tac. A. 1, 74: pernicies in accusatorem vertit, id. ib. 11, 37; id. H. 3, 27: in nepotum Perniciem, Hor. C. 2, 13, 4.
  2. II. Transf., concr., a person or thing that is ruinous or baleful, destruction, ruin, bane, pest: egredere, erilis pernicies, ex aedibus, Plaut. Most. 1, 1, 3 Lorenz (Ritschl, permicies): perlecebrae, pernicies, adulescentum exitium, id. As. 1, 2, 7: legirupa, pernicies adulescentum, id. Ps. 1, 3, 130; cf.: leno, pernicies communis adulescentium, Ter. Ad. 2, 1, 34: pernicies provinciae Siciliae, i. e. Verres, Cic. Verr. 1, 1, 2: illam perniciem exstinxit ac sustulit, i. e. Clodius, id. Mil. 31, 84: lymphae vini pernicies, Cat. 27, 5: eripite hanc pestem perniciemque mihi, id. 76, 20: pernicies et tempestas barathrumque macelli, Hor. Ep. 1, 15, 31.
    Of animals, Col. 8, 14, 9.