suddenly and unexpectedly; "rain caught them unawares"; "sorrow comes to all, and to the young it comes with bittered agony because it takes them unawares"- A.Lincoln
without forethought or plan; inadvertently; "came upon the diamond unawares"
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"