For one single day turning to face nameless severe misfortune (8)
I believe the answer is:
disaster
'misfortune' is the definition.
(I know that disaster is a type of adversity)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for disaster that I've seen before include "terrible trouble" , "awful situation" , "Catastrophic occurrence" , "Catastrophe, tragedy" , "Terrible calamity" .)