Pernícitas, pen. cor. tâtis, f. g. Plin. Swiftnesse.Pernicitas & velocitas.Cic.Eximiæ pernicitatis homines. Plin. Passing notable swifte men.Adempta equorum pernicitate. Taci. Horses not beeing able to make any speede.Pernicitas pedum inerat. Liu, He was swift of foote.Electi milites ad pernicitatem Cæs.
Lewis and Short: Latin dictionary
pernīcĭtas, ātis, f. [pernix], nimbleness, briskness, agility, swiftness, fleetness (class.): pernicitas deserit: consitus sum senectute, Plaut. Men. 5, 2, 4: adde pernicitatem et velocitatem, Cic. Tusc. 5, 15, 45; Caes. B. C. 3, 84: pedum pernicitas, Liv. 9, 16: homines saltatim currentes, vivacissimae pernicitatis, Gell. 9, 4, 9: equorum, Tac. H. 1, 79.