Noah Webster's Dictionary (a.) Tending to cause death or disease; noxious; pernicious; mischievous.

Multi-Version Concordance Pestilent (1 Occurrence) Acts 24:5 For we have found this man a pestilent fellow, and a mover of sedition among all the Jews throughout the world, and a ringleader of the sect of the Nazarenes: (KJV ASV WBS RSV)