Lewis Short
(adjective) : exĭtĭālis, e, id.
* Destructive, fatal, deadly (rare but class.): exitus exitiales habere, * Cic. Verr. 2, 5, 6, § 12: donum,Verg. A. 2, 31: scelus,id. ib. 6, 511: animalia venenata magis exitialia, si, etc.,Plin. 10, 72, 93, § 198: criminosum et exitiale habebatur,Suet. Calig. 50.—Adv. exĭtĭālĭter, perniciously: amare,Aug. Conf. 6, 7.
Charlton T. Lewis, Charles Short, A Latin Dictionary