Mood affected destiny (4)
I believe the answer is:
doom
'destiny' is the definition.
(doom is a kind of destiny)
'mood affected' is the wordplay.
'affected' indicates anagramming the letters.
'mood' anagrammed gives 'DOOM'.
(Other definitions for doom that I've seen before include "Condemn (to certain death?)" , "Terrible fate; death" , "Mood for damnation" , "Bad destiny" , "Fate; ruin" .)