so frightened as to be unable to move; stunned or paralyzed with terror; "petrified with fear"; "she was petrified by the eerie sound"; "too numb with fear to move"
delivered at the moment of parting as if in flight or retreat; "paused to deliver a parting shot at the door"; "a Parthian volley of expletives from Uncle Billy"- Bret Harte
a pernicious and malign influence that is hard to get rid of; "racism is a pestilence at the heart of the nation"; "according to him, I was the canker in their midst"