Mishap, misadventure (8)
I believe the answer is:
accident
I believe this is a double definition.
'mishap' is the first definition.
(I've seen this before)
'misadventure' is the second definition.
(I've seen this before)
(Other definitions for accident that I've seen before include "fluke" , "Unforseen misfortune" , "Chance occurrence." , "disaster" , "Collision" .)